feat(client/android): per-AU attribution for latency excursions

The e2e spikes WP2 surfaced (79-106 ms against a 9-16 ms p50) could not be
diagnosed from what we log. Window maxima cannot say WHERE a 90 ms frame spent
its time, because the per-stage maxima in a window are generally different
frames. Attribution has to be captured per AU, for the offending AU.

`debug.punktfunk.spike_ms` arms a watch: every AU whose capture->reassembled
latency crosses the threshold is logged to `pf.spike` with the host's own
pipeline time for that same AU (from the 0xCF timing plane), the remainder on
the wire, the AU's size, and the gap since the previous AU was reassembled.
That last field is what separates "this frame was slow" from "the stream
stalled and then burst" — indistinguishable in any percentile. Off by default,
so it costs nothing until someone asks.

Also moves the 0xCF drain OUT of the HUD gate. It carries the host's per-AU
pipeline time and the phase-lock ACK, neither of which had any business being
invisible with the HUD down — the same HUD-gating trap this client has now hit
three times.

What it found immediately, on .173 over Wi-Fi:

  idx=2383 hostnetMs=72.8 hostMs=4.6 netMs=68.2 gapMs=69.5
  idx=2384 hostnetMs=66.4 hostMs=4.9 netMs=61.6 gapMs=1.8
  idx=2385 hostnetMs=62.2 hostMs=4.9 netMs=57.3 gapMs=3.8
  ...
  idx=2420 hostnetMs=69.2 hostMs=4.3 netMs=65.0 gapMs=69.3

A ~69 ms window where nothing is delivered, then a burst that drains the
backlog, recurring every ~305 ms. Across 112 attributed frames the host
pipeline is 2.0-8.0 ms (mean 3.9) and never spikes: the excursion is entirely
wire time. Our Wi-Fi low-latency lock is confirmed active throughout
(`dumpsys wifi`: both locks held, uid in the low-latency watchlist,
operation mode 4), so this is NOT the power-save trap StreamScreen already
defends against — that defence is working and is not sufficient.

Gates: cargo ndk check + clippy arm64 clean (the 5 warnings are pre-existing
and in other files); fmt clean.

.gitea/workflows/android.yml

@@ -160,6 +160,14 @@ jobs:
           key: gradle-${{ hashFiles('clients/android/**/*.gradle.kts', 'clients/android/gradle/wrapper/gradle-wrapper.properties') }}
           restore-keys: gradle-
 
+      # The kit's JVM unit tests — the pure parsers, migrations and feedback policies. They were
+      # running nowhere: this workflow only assembled, and android-screenshots.yml runs the :app
+      # module's tests, so nothing enforced :kit's. Cheap (a couple of seconds against an already
+      # built module) and it is the only automated cover those behaviours have.
+      - name: kit unit tests
+        working-directory: clients/android
+        run: ./gradlew :kit:testDebugUnitTest --stacktrace
+
       - name: assembleDebug (cargo-ndk → jniLibs → APK)
         working-directory: clients/android
         env:

.gitea/workflows/announce.yml

@@ -41,9 +41,23 @@ jobs:
         env:
           REGISTRY_TOKEN: ${{ secrets.REGISTRY_TOKEN }}
           UPDATE_MANIFEST_KEY: ${{ secrets.UPDATE_MANIFEST_KEY }}
+          # Through the ENVIRONMENT, never interpolated into the script body. A `${{ }}` expansion
+          # is a raw textual substitution performed BEFORE the shell sees the line, so a
+          # workflow_dispatch input containing shell syntax executes as this step — and this is the
+          # step holding UPDATE_MANIFEST_KEY, the Ed25519 key every host pins to decide whether an
+          # update is real (2026-08-05 review H-6). As `$INPUT_TAG` it is only ever data.
+          INPUT_TAG: ${{ inputs.tag }}
         run: |
           set -euo pipefail
-          TAG="${{ inputs.tag }}"
+          TAG="$INPUT_TAG"
+          # Shape-check before the value reaches a URL or a filename: tags are `vX.Y.Z[-suffix]`.
+          case "$TAG" in
+            v[0-9]*) ;;
+            *) echo "refusing to publish for a tag that is not vX.Y.Z: $TAG" >&2; exit 1 ;;
+          esac
+          case "$TAG" in
+            *[!A-Za-z0-9.+_-]*) echo "tag has characters no release tag has: $TAG" >&2; exit 1 ;;
+          esac
           case "$TAG" in
             *-*) echo "pre-release tag $TAG — not publishing to the stable update feed"; exit 0 ;;
           esac
@@ -67,4 +81,7 @@ jobs:
           GITEA_TOKEN: ${{ secrets.REGISTRY_TOKEN }}
           DISCORD_RELEASE_WEBHOOK: ${{ secrets.DISCORD_RELEASE_WEBHOOK }}
           ALLOW_PRERELEASE: ${{ inputs.allow_prerelease }}
-        run: bash scripts/ci/discord-announce.sh "${{ inputs.tag }}"
+          # Same reasoning as the publish step above: the input is data in the environment, never
+          # text spliced into the command line.
+          INPUT_TAG: ${{ inputs.tag }}
+        run: bash scripts/ci/discord-announce.sh "$INPUT_TAG"

.gitea/workflows/bench-gpu.yml

@@ -29,4 +29,9 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - name: Tier-3 GPU stream benchmark
-        run: bash scripts/bench/gpu-stream.sh "${{ inputs.mode || '1920x1080x120' }}" 12
+        # Through the environment, not interpolated into the command line: a `${{ }}` expansion is
+        # substituted before the shell parses the line, so an input carrying shell syntax would run
+        # as this step (2026-08-05 review H-6).
+        env:
+          BENCH_MODE: ${{ inputs.mode || '1920x1080x120' }}
+        run: bash scripts/bench/gpu-stream.sh "$BENCH_MODE" 12

.gitea/workflows/docker.yml

@@ -20,6 +20,24 @@
 # REGISTRY_TOKEN: repo Actions secret, a PAT with write:package scope (app images only —
 # the LAN registry is unauthenticated inside the LAN).
 #
+# ⚠ OPEN FINDING — security-review-2026-08-05 H-6. That parenthetical is the whole problem.
+# Every secret-bearing job in this repo runs INSIDE an image pulled from this registry by a
+# MUTABLE tag (`:latest`), and the registry accepts pushes from any LAN peer. Attacker position #1
+# of the project's own threat model — an unauthenticated LAN peer — therefore does not need to
+# break any signing logic: they push one tag, and the next android.yml run executes their code in
+# the same job that does `echo "$RELEASE_KEYSTORE_BASE64" | base64 -d > release.jks`. Same shape
+# for rpm.yml (RPM_GPG_PRIVATE_KEY), android-promote.yml (SERVICE_ACCOUNT_JSON), and every other
+# consumer listed by `grep -l 192.168.1.58:5010 .gitea/workflows/`.
+#
+# The fix is two halves and only one of them lives in this repo:
+#   1. INFRA (unom/infra, runners/ci-core/): put auth in front of the registry, or move the
+#      builder images to git.unom.io where pushes are already authenticated.
+#   2. HERE: once pushes are authenticated, pin consumers by `@sha256:` digest rather than
+#      `:latest`, so a compromised push cannot retroactively change what a green run built.
+#      Pinning by tag — including the content-keyed `$KEY` tags below — is NOT sufficient while
+#      the registry is open, because a tag can simply be overwritten.
+# Neither half is done. The content-keying below bounds rebuild churn; it is not a trust boundary.
+#
 # Bootstrap note: consuming workflows pull <LAN>/punktfunk-rust-ci:latest, so the LAN
 # registry must hold a seeded :latest once (done 2026-07-29 from the last Gitea-registry
 # images); after that, this workflow keeps :latest current whenever ci/ changes.

.gitea/workflows/sbom.yml

@@ -38,10 +38,18 @@ jobs:
         with:
           fetch-depth: 0
       # Pinned syft (keep in sync with the version validated against this repo; bump deliberately).
+      #
+      # The BINARY version was pinned; the INSTALLER was not — it was fetched from `main` and piped
+      # into a shell, so whatever that branch happened to say at job time ran here, with the job's
+      # environment (2026-08-05 review H-6). Pinning the script to the same tag as the binary makes
+      # the whole step reproducible: bump the tag in both places together.
       - name: Install syft
+        env:
+          SYFT_VERSION: v1.49.0
         run: |
-          curl -sSfL https://raw.githubusercontent.com/anchore/syft/main/install.sh \
-            | sh -s -- -b /usr/local/bin v1.49.0
+          set -euo pipefail
+          curl -sSfL "https://raw.githubusercontent.com/anchore/syft/${SYFT_VERSION}/install.sh" \
+            | sh -s -- -b /usr/local/bin "$SYFT_VERSION"
       - name: Generate SBOM
         run: |
           git config --global --add safe.directory "$PWD"

Cargo.lock

@@ -2893,6 +2893,7 @@ dependencies = [
  "ureq",
  "wasapi",
  "windows 0.62.2 (git+https://github.com/microsoft/windows-rs?rev=acb5a1a7441033d9312b16842af02eb0c2b403dc)",
+ "winreg",
 ]
 
 [[package]]
@@ -3346,6 +3347,8 @@ dependencies = [
  "opus",
  "punktfunk-core",
  "tracing",
+ "uac-host",
+ "usbfs-iso",
 ]
 
 [[package]]
@@ -4985,6 +4988,14 @@ version = "1.20.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b6f5e870be6c3b371b77fe0ee0bafb859fa4964b4404c27de1d380043c4dda20"
 
+[[package]]
+name = "uac-host"
+version = "0.1.0"
+source = "git+https://github.com/unom-io/usbfs-iso?rev=f3de1fd62cec271d07f45664dc464f23e423e721#f3de1fd62cec271d07f45664dc464f23e423e721"
+dependencies = [
+ "usbfs-iso",
+]
+
 [[package]]
 name = "uds_windows"
 version = "1.2.1"
@@ -5064,6 +5075,14 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "usbfs-iso"
+version = "0.1.0"
+source = "git+https://github.com/unom-io/usbfs-iso?rev=f3de1fd62cec271d07f45664dc464f23e423e721#f3de1fd62cec271d07f45664dc464f23e423e721"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "usbip-sim"
 version = "0.8.0"

clients/android/app/src/main/kotlin/io/unom/punktfunk/ControllersScreen.kt

@@ -410,17 +410,68 @@ private fun DsRow(usbDev: android.hardware.usb.UsbDevice) {
                         Text("Grant USB access")
                     }
                 }
-                else -> Text(
-                    if (model == DsDevice.Model.DUALSHOCK4) {
-                        "Ready — captured at stream start: rumble, lightbar and gyro are " +
-                            "driven directly."
-                    } else {
-                        "Ready — captured at stream start: rumble, adaptive triggers, lightbar " +
-                            "and gyro are driven directly."
-                    },
-                    style = MaterialTheme.typography.bodySmall,
-                    color = MaterialTheme.colorScheme.onSurfaceVariant,
-                )
+                else -> {
+                    Text(
+                        if (model == DsDevice.Model.DUALSHOCK4) {
+                            "Ready — captured at stream start: rumble, lightbar and gyro are " +
+                                "driven directly."
+                        } else {
+                            "Ready — captured at stream start: rumble, adaptive triggers, lightbar " +
+                                "and gyro are driven directly."
+                        },
+                        style = MaterialTheme.typography.bodySmall,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant,
+                    )
+                    // Pad-audio self test. Deliberately reachable WITHOUT a stream: it exists to
+                    // answer "can this phone drive this pad's audio endpoint at all", and gating
+                    // that behind a live session would make it depend on the very thing one wants
+                    // to rule out when a session misbehaves. DualSense only — the DS4 has no
+                    // 4-channel haptics device.
+                    if (model != DsDevice.Model.DUALSHOCK4) {
+                        var testing by remember { mutableStateOf(false) }
+                        var result by remember { mutableStateOf<String?>(null) }
+                        result?.let {
+                            Text(
+                                it,
+                                style = MaterialTheme.typography.bodySmall,
+                                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                            )
+                        }
+                        OutlinedButton(
+                            enabled = !testing,
+                            onClick = {
+                                testing = true
+                                result = null
+                                Thread({
+                                    // Its OWN connection: the renderer's descriptor must never be
+                                    // shared with another transfer engine, and that applies to
+                                    // this test as much as to the real path.
+                                    val conn = runCatching { usbManager.openDevice(usbDev) }.getOrNull()
+                                    val fd = conn?.fileDescriptor ?: -1
+                                    val r = if (fd >= 0) {
+                                        io.unom.punktfunk.kit.NativeBridge.nativePadAudioSelfTest(fd, 3, 60)
+                                    } else {
+                                        -1
+                                    }
+                                    conn?.close()
+                                    val msg = when {
+                                        r > 0 -> "Haptics test passed — $r frames to the pad."
+                                        r == -1 -> "Could not open the pad's audio interface. " +
+                                            "Some kernels refuse it; the pad still works normally."
+                                        r == -2 -> "The audio stream stopped part-way."
+                                        else -> "The stream opened but no audio reached the pad."
+                                    }
+                                    android.os.Handler(android.os.Looper.getMainLooper()).post {
+                                        result = msg
+                                        testing = false
+                                    }
+                                }, "pf-pad-selftest-ui").start()
+                            },
+                        ) {
+                            Text(if (testing) "Testing…" else "Test haptics")
+                        }
+                    }
+                }
             }
         }
     }

clients/android/app/src/main/kotlin/io/unom/punktfunk/HostConnect.kt

@@ -84,6 +84,9 @@ suspend fun connectToHost(
             // The host's approval-list / trust-store label for this device — the same
             // Build.MODEL convention the pairing dialogs use for nativePair.
             Build.MODEL ?: "Android",
+            // Tier-A pad audio: ask for the 0xD1 plane only when a setting would render it, so a
+            // user with it off does not make the host provision endpoints it will never feed.
+            settings.padHaptics || settings.padSpeaker,
         )
     }
 }

clients/android/app/src/main/kotlin/io/unom/punktfunk/Settings.kt

@@ -170,6 +170,26 @@ data class Settings(
      */
     val dsCapture: Boolean = true,
 
+    /**
+     * Render the host's DualSense **voice-coil haptics** on a captured USB pad (tier A).
+     *
+     * The pad's own 4-channel audio device carries them, driven directly over usbfs — Android's
+     * audio framework denylists that device by VID/PID, so there is no supported route to it. The
+     * two kinds are arbitrated rather than mixed, and on evidence: wire rumble is suppressed only
+     * while haptics frames are actually arriving, so a title that drives classic rumble and sends
+     * no haptics audio keeps rumbling. Off, or on an uncaptured/Bluetooth pad, the pad stays on
+     * ordinary rumble (tier C), which on this client already drives the same actuators.
+     */
+    val padHaptics: Boolean = true,
+
+    /**
+     * Render the pad's **built-in speaker** on a captured USB pad. Independent of [padHaptics] —
+     * the host sends the two as separate streams and either can play alone. Off by default: the
+     * speaker is a small, easily-startling loudspeaker in the user's hands, and unlike haptics it
+     * duplicates audio they are already hearing.
+     */
+    val padSpeaker: Boolean = false,
+
     /**
      * How a physical mouse drives the host — the cross-client mouse model (see [MouseMode]).
      * [MouseMode.DESKTOP] (default here) points absolutely; [MouseMode.CAPTURE] locks the pointer
@@ -271,6 +291,8 @@ class SettingsStore(context: Context) {
         rumbleOnPhone = prefs.getBoolean(K_RUMBLE_ON_PHONE, false),
         sc2Capture = prefs.getBoolean(K_SC2_CAPTURE, true),
         dsCapture = prefs.getBoolean(K_DS_CAPTURE, true),
+        padHaptics = prefs.getBoolean(K_PAD_HAPTICS, true),
+        padSpeaker = prefs.getBoolean(K_PAD_SPEAKER, false),
         mouseMode = prefs.getString(K_MOUSE_MODE, null)
             ?.let { name -> MouseMode.entries.firstOrNull { it.storedName == name } }
             // Migration: the pre-enum Boolean "pointer_capture" (true = lock the pointer). Its
@@ -308,6 +330,8 @@ class SettingsStore(context: Context) {
             .putBoolean(K_RUMBLE_ON_PHONE, s.rumbleOnPhone)
             .putBoolean(K_SC2_CAPTURE, s.sc2Capture)
             .putBoolean(K_DS_CAPTURE, s.dsCapture)
+            .putBoolean(K_PAD_HAPTICS, s.padHaptics)
+            .putBoolean(K_PAD_SPEAKER, s.padSpeaker)
             .putString(K_MOUSE_MODE, s.mouseMode.storedName)
             .putBoolean(K_INVERT_SCROLL, s.invertScroll)
             .apply()
@@ -355,6 +379,8 @@ class SettingsStore(context: Context) {
         const val K_RUMBLE_ON_PHONE = "rumble_on_phone"
         const val K_SC2_CAPTURE = "sc2_capture"
         const val K_DS_CAPTURE = "ds_capture"
+        const val K_PAD_HAPTICS = "pad_haptics"
+        const val K_PAD_SPEAKER = "pad_speaker"
         const val K_MOUSE_MODE = "mouse_mode"
 
         /** Legacy Boolean the [K_MOUSE_MODE] enum replaced — read once for migration, never written. */

clients/android/app/src/main/kotlin/io/unom/punktfunk/SettingsScreen.kt

@@ -896,6 +896,22 @@ private fun ControllerSettings(s: Settings, update: (Settings) -> Unit, onOpenCo
                 enabled = s.gamepadForwarding,
                 onCheckedChange = { on -> update(s.copy(dsCapture = on)) },
             )
+            // Both only ever apply to a captured pad, so they follow that row and gate on it.
+            ToggleRow(
+                title = "Controller haptics",
+                subtitle = "Play the host's fine-grained DualSense haptics on the pad itself — " +
+                    "the pad keeps ordinary rumble for games that don't send them",
+                checked = s.padHaptics,
+                enabled = s.gamepadForwarding && s.dsCapture,
+                onCheckedChange = { on -> update(s.copy(padHaptics = on)) },
+            )
+            ToggleRow(
+                title = "Controller speaker",
+                subtitle = "Play audio the game sends to the controller's own speaker",
+                checked = s.padSpeaker,
+                enabled = s.gamepadForwarding && s.dsCapture,
+                onCheckedChange = { on -> update(s.copy(padSpeaker = on)) },
+            )
         }
     }
 }

clients/android/app/src/main/kotlin/io/unom/punktfunk/StreamScreen.kt

@@ -507,6 +507,28 @@ fun StreamScreen(session: ActiveSession, onDisconnect: () -> Unit) {
         var dsUsbReceiver: BroadcastReceiver? = null
         if (ds != null) {
             feedback.sink = ds
+            // Tier-A pad audio: render the host's 0xD1 streams on the pad's own 4-channel USB
+            // audio device. Bound here rather than inside DsCapture because the session handle
+            // lives at this layer; DsCapture decides WHEN (it knows the wire index and the link
+            // lifetime), this decides WHETHER.
+            if (initialSettings.padHaptics || initialSettings.padSpeaker) {
+                ds.padAudio = object : DsCapture.PadAudioHook {
+                    override fun start(pad: Int, fd: Int) {
+                        val ok = NativeBridge.nativeStartPadAudio(
+                            handle,
+                            pad,
+                            fd,
+                            initialSettings.padHaptics,
+                            initialSettings.padSpeaker,
+                        )
+                        Log.i("punktfunk", "pad audio on pad $pad: ${if (ok) "started" else "unavailable"}")
+                    }
+
+                    // Returns only once the render thread is joined — DsCapture calls this before
+                    // closing the connection whose descriptor that thread borrows.
+                    override fun stop(pad: Int) = NativeBridge.nativeStopPadAudio(handle, pad)
+                }
+            }
             val usbManager = context.getSystemService(Context.USB_SERVICE) as UsbManager
             val usbDev = ds.findUsbDevice()
             when {

clients/android/kit/src/main/kotlin/io/unom/punktfunk/kit/DsCapture.kt

@@ -23,8 +23,9 @@ import android.view.InputDevice
  * Input: parse ([DsDevice.parseState]) → typed mirror on an [GamepadRouter.ExternalPad] (buttons
  * diffed, axes on-change — the exit chord participates like any pad) + the rich plane (touch
  * normalized to the wire's 0..65535 screen space on-change; motion forwarded per report in raw
- * device units, the wire's contract). The wire slot is claimed lazily on the FIRST parsed report
- * and freed on unplug/[stop], so indices never leak.
+ * device units, the wire's contract). The wire slot is claimed when the capture engages, with the
+ * first parsed report as the fallback for a claim that found no free index, and freed on
+ * unplug/[stop], so indices never leak.
  *
  * Feedback: implements [GamepadFeedback.PadFeedbackSink] — rumble / trigger / lightbar / player
  * LED events addressed to this pad's wire index become USB output reports on the physical pad
@@ -78,6 +79,33 @@ class DsCapture(
     @Volatile
     var onActiveChanged: ((active: Boolean) -> Unit)? = null
 
+    /**
+     * Tier-A pad audio, bound by the app layer (which owns the session handle).
+     *
+     * [start] is called once the router has assigned this pad a wire index, which the host uses to
+     * address the `0xD1` stream. [stop] is called **before** the USB link closes — on [stop] and on
+     * unplug alike — and must not return until nothing is still writing to the descriptor.
+     */
+    interface PadAudioHook {
+        fun start(pad: Int, fd: Int)
+        fun stop(pad: Int)
+    }
+
+    @Volatile
+    var padAudio: PadAudioHook? = null
+
+    /** True once [PadAudioHook.start] has run for the current capture, so it fires exactly once. */
+    @Volatile private var padAudioStarted = false
+
+    /**
+     * The renderer's OWN connection to the pad.
+     *
+     * It must not share [usb]'s descriptor: two transfer engines on one usbfs descriptor reap each
+     * other's completions (see [HidUsbLink.openAuxConnection]), which strands both the HID reader
+     * and the audio ring. Closed only after the hook's stop has returned.
+     */
+    @Volatile private var padAudioConn: android.hardware.usb.UsbDeviceConnection? = null
+
     val isActive: Boolean get() = model != null
 
     /** First attached Sony USB pad, for the permission flow. Needs no permission to enumerate. */
@@ -105,18 +133,28 @@ class DsCapture(
         // (the same init hid-playstation/SDL send on open).
         if (m != DsDevice.Model.DUALSHOCK4) usb.writeRaw(0, DsDevice.ds5InitReport(m))
         Log.i(TAG, "Sony pad captured over USB: PID=0x%04x model=%s".format(dev.productId, m))
+        ensureSlot(m)
         onActiveChanged?.invoke(true)
         return true
     }
 
     /** Stop the link and free the wire slot (host tears the virtual pad down). Idempotent. */
     fun stop() {
+        // Before anything touches the link: the pad-audio renderer borrows this connection's
+        // descriptor, and `usb.stop()` closes it. The hook does not return until its thread is
+        // joined, so ordering this first is what makes the borrow sound.
+        stopPadAudio()
         val m = model
         if (m != null) {
             // The interfaces are about to release with the kernel driver still detached — a
             // mid-rumble teardown would leave the motors running with nobody to stop them.
             // EP0-direct (the reader thread is stopping; the queue would never drain).
-            usb.writeControl(stopReport(m))
+            // Nothing can retry after this point, so a failure is worth saying out loud: it is
+            // the difference between a quiet pad and one that buzzes until it is unplugged.
+            if (!usb.writeControl(stopReport(m))) Log.w(TAG, "teardown rumble stop was not written")
+            // Motors silenced above; this hands back the lightbar, player LEDs and adaptive
+            // triggers the game was holding, which outlive the link just as stubbornly.
+            resetRichFeedback(m)
         }
         disarmBackstop()
         usb.stop()
@@ -131,20 +169,119 @@ class DsCapture(
     private fun onReport(report: ByteArray, len: Int) {
         val m = model ?: return
         if (!DsDevice.parseState(m, report, len, state)) return
-        val p = pad ?: router.openExternal(m.pref)?.also {
-            pad = it
-            Log.i(TAG, "captured $m → wire pad ${it.index}")
-        } ?: return // all 16 wire indices taken — drop until one frees
+        // Normally claimed already, at capture time; this is the retry for a capture that engaged
+        // while every wire index was taken.
+        val p = pad ?: ensureSlot(m) ?: return // all 16 taken — drop until one frees
         mirrorTyped(p)
         mirrorRich(p, m)
     }
 
+    /**
+     * Claim this capture's wire slot and start pad audio on it. Idempotent; null when all 16
+     * indices are taken.
+     *
+     * Claimed when the capture engages rather than on the first report, because a pad that reports
+     * nothing is still a pad: with the lazy claim, a captured-but-silent pad left the host with no
+     * arrival, hence no virtual pad, no pad-audio capability and so no `0xD1` — a renderer sitting
+     * at zero frames, indistinguishable from a broken pipeline (it took a physical replug to
+     * clear). Callable from the main thread (capture start) and the link thread (the fallback).
+     */
+    @Synchronized
+    private fun ensureSlot(m: DsDevice.Model): GamepadRouter.ExternalPad? {
+        pad?.let { return it }
+        val p = router.openExternal(m.pref) ?: return null
+        pad = p
+        Log.i(TAG, "captured $m → wire pad ${p.index}")
+        // The wire index exists from here on, and the host addresses pad audio by it.
+        startPadAudio(p.index)
+        return p
+    }
+
+    /** Hand the renderer its own descriptor. Caller holds the monitor; fires once per capture. */
+    private fun startPadAudio(index: Int) {
+        val hook = padAudio ?: return
+        if (padAudioStarted) return
+        // A dedicated connection, NOT usb.fileDescriptor — see padAudioConn.
+        val conn = usb.openAuxConnection()
+        val fd = conn?.fileDescriptor ?: -1
+        if (fd < 0) {
+            conn?.close()
+            Log.w(TAG, "pad audio: could not open a second USB connection")
+            return
+        }
+        padAudioConn = conn
+        padAudioStarted = true
+        // Real-world self test, opt-in: `adb shell setprop debug.punktfunk.pad_audio_selftest 3`
+        // drives the voice coils for N seconds through the actual client path before the renderer
+        // takes over — the one check that proves the descriptor, the interface claim and the write
+        // path all work on THIS device, without needing a host to be streaming. Same convention as
+        // debug.punktfunk.force_parts.
+        val secs = runCatching {
+            Class.forName("android.os.SystemProperties")
+                .getMethod("get", String::class.java, String::class.java)
+                .invoke(null, "debug.punktfunk.pad_audio_selftest", "0") as String
+        }.getOrNull()?.toIntOrNull() ?: 0
+        if (secs > 0) {
+            // Diagnostic mode: the self test OWNS this descriptor for the capture, and the renderer
+            // must not also drive it — two engines on one usbfs descriptor reap each other's
+            // completions, which is precisely the fault this test exists to expose.
+            Thread({
+                val r = NativeBridge.nativePadAudioSelfTest(fd, secs, 60)
+                Log.i(TAG, "pad audio self-test → ${if (r > 0) "PASS ($r frames)" else "FAIL ($r)"}")
+            }, "pf-pad-selftest").start()
+        } else {
+            // B6: hand the coils back before the first haptics frame. Any rumble earlier in this
+            // session asserted HAPTICS_SELECT, which firmware-mutes them, and nothing else ever
+            // clears it — so without this the stream renders into a muted actuator and looks for
+            // all the world like the host is sending nothing.
+            restoreAudioHaptics()
+            hook.start(index, fd)
+        }
+    }
+
+    /**
+     * B6: clear the rumble/haptics-select bits so the pad's voice coils answer the audio-haptics
+     * path again. EP0-direct, like the other out-of-band writes here: this has to land even when
+     * the interrupt-OUT queue is busy or draining, and it is idempotent.
+     */
+    private fun restoreAudioHaptics() {
+        val m = model ?: return
+        if (m == DsDevice.Model.DUALSHOCK4) return // no voice coils, no audio-haptics path
+        if (!usb.writeControl(DsDevice.ds5AudioHapticsReport(m))) {
+            Log.w(TAG, "pad audio: could not hand the coils back to audio haptics")
+        }
+    }
+
+    /**
+     * Stop the renderer, then close the connection whose descriptor it borrows — in that order.
+     *
+     * Runs on [stop] and on unplug alike. Skipping it on unplug left the render thread writing to a
+     * descriptor whose device was gone, leaked the connection, and — because the started flag stayed
+     * set and the native tier-A registry stayed armed for that index — cost the pad both its pad
+     * audio and its wire rumble on the way back in.
+     */
+    @Synchronized
+    private fun stopPadAudio() {
+        if (!padAudioStarted) return
+        padAudioStarted = false
+        // The hook's stop joins the render thread, so nothing is using the descriptor once it
+        // returns — only then is it safe to close the connection that owns it.
+        pad?.let { padAudio?.stop(it.index) }
+        padAudioConn?.close()
+        padAudioConn = null
+    }
+
     private fun onLinkClosed() {
         Log.i(TAG, "Sony USB link closed (unplug)")
+        // Before releaseSlot(), which forgets the wire index the renderer is addressed by.
+        stopPadAudio()
         disarmBackstop()
         val wasActive = model != null
         model = null
         releaseSlot()
+        // Release the transport too: the link only *signals* the drop, so without this an unplug
+        // left its connection open, its interfaces claimed and its detach receiver registered.
+        usb.stop()
         if (wasActive) onActiveChanged?.invoke(false)
     }
 
@@ -216,17 +353,24 @@ class DsCapture(
 
     override fun rumble(pad: Int, low: Int, high: Int, backstopMs: Long) {
         val m = model ?: return
-        if (low == 0 && high == 0) {
-            disarmBackstop()
-        } else {
-            armBackstop(backstopMs)
-        }
-        if (m == DsDevice.Model.DUALSHOCK4) {
+        val stop = low == 0 && high == 0
+        if (!stop) armBackstop(backstopMs)
+        val sent = if (m == DsDevice.Model.DUALSHOCK4) {
             ds4Low = low
             ds4High = high
             writeDs4()
         } else {
-            usb.writeRaw(0, DsDevice.ds5RumbleReport(m, low, high))
+            usb.writeRaw(0, DsDevice.ds5RumbleReport(m, low, high), OutReportQueue.KEY_RUMBLE)
+        }
+        if (stop) {
+            // Disarm only once the stop is actually on its way. Dropping the net *before* the
+            // write — as this used to — meant a discarded stop left the motors running with
+            // nothing scheduled to try again; a USB pad holds its last level until told zero.
+            if (sent) disarmBackstop() else armBackstop(STOP_RETRY_MS)
+            // B6: the stop report just re-asserted HAPTICS_SELECT on its way past, so if a
+            // haptics stream is live the coils it drives were muted by the very write that
+            // silenced the motors. Give them back.
+            if (sent && padAudioStarted) restoreAudioHaptics()
         }
     }
 
@@ -252,6 +396,9 @@ class DsCapture(
         usb.writeRaw(0, DsDevice.ds5TriggerReport(m, which, effect))
     }
 
+    // Coalescable: the DS4's write is full-state (motors AND lightbar, rebuilt from the current
+    // fields on every call), so a newer one supersedes an older one wholesale — nothing is lost by
+    // collapsing a backlog of them down to the last.
     private fun writeDs4() = usb.writeRaw(
         0,
         DsDevice.ds4Report(
@@ -261,8 +408,38 @@ class DsCapture(
             (ds4Rgb shr 8) and 0xFF,
             ds4Rgb and 0xFF,
         ),
+        OutReportQueue.KEY_RUMBLE,
     )
 
+    /**
+     * Hand the pad back neutral: adaptive triggers released, lightbar dark, player LEDs clear.
+     *
+     * Rumble stops the moment nothing renews it, but these are LATCHED in the controller's
+     * firmware — they outlive the stream, the app, and being unplugged. Ending a session while a
+     * game held a weapon's trigger resistance left the physical trigger stiff afterwards, with
+     * nothing to release it but another game that happens to set one.
+     *
+     * EP0-direct like the rumble stop above: the reader thread is stopping, so the interrupt-OUT
+     * queue would never drain. Writes are best-effort — the pad may already be gone.
+     */
+    private fun resetRichFeedback(m: DsDevice.Model) {
+        if (m == DsDevice.Model.DUALSHOCK4) {
+            // No adaptive triggers or player LEDs on a DS4, and its write is full-state, so
+            // blacking the lightbar is a single composed report.
+            ds4Rgb = 0
+            usb.writeControl(DsDevice.ds4Report(0, 0, 0, 0, 0))
+            return
+        }
+        // An all-zero effect block is mode 0x00 — no effect — which is what releases the trigger.
+        for (which in 0..1) {
+            usb.writeControl(
+                DsDevice.ds5TriggerReport(m, which, ByteArray(DsDevice.TRIGGER_EFFECT_LEN)),
+            )
+        }
+        usb.writeControl(DsDevice.ds5LightbarReport(m, 0, 0, 0))
+        usb.writeControl(DsDevice.ds5PlayerLedsReport(m, 0))
+    }
+
     /** The report that stops the motors. The DS4's is a full-state write, so it zeroes the
      *  composed motor state and carries the current lightbar rather than blacking it out. */
     private fun stopReport(m: DsDevice.Model): ByteArray = if (m == DsDevice.Model.DUALSHOCK4) {
@@ -284,7 +461,12 @@ class DsCapture(
         backstop?.let { mainHandler.removeCallbacks(it) }
         val r = Runnable {
             backstop = null
-            model?.let { usb.writeRaw(0, stopReport(it)) }
+            val m = model ?: return@Runnable
+            // The net itself can be refused (a full queue, a connection going away). Re-arm rather
+            // than give up: this is the last thing between a stalled poll thread and a pad that
+            // buzzes until it is unplugged. It stops re-arming as soon as the link closes, which
+            // clears `model` and disarms.
+            if (!usb.writeRaw(0, stopReport(m), OutReportQueue.KEY_RUMBLE)) armBackstop(STOP_RETRY_MS)
         }
         backstop = r
         mainHandler.postDelayed(r, ms.coerceAtLeast(1))
@@ -297,5 +479,9 @@ class DsCapture(
 
     private companion object {
         const val TAG = "DsCapture"
+
+        /** How soon to retry a rumble stop whose write was rejected. Short: the motors are running
+         *  and the host has already moved on, so nothing else is coming to silence them. */
+        const val STOP_RETRY_MS = 100L
     }
 }

clients/android/kit/src/main/kotlin/io/unom/punktfunk/kit/DsDevice.kt

@@ -276,11 +276,26 @@ object DsDevice {
      * the classic compat-vibration path AND `VIBRATION2` (firmware ≥ 2.24's full-range replot;
      * older firmware ignores the unknown flag2 bit) — the host parser accepts either.
      */
+    /**
+     * B6: hand the voice coils back to the audio-haptics path.
+     *
+     * Every [ds5RumbleReport] asserts `HAPTICS_SELECT` (flag0 bit1), which is SDL's
+     * "disable audio haptics" bit — the firmware mutes the coils the 0xD1 haptics stream drives.
+     * Until now NOTHING ever cleared it again, so a single rumble anywhere in a session left tier-A
+     * haptics silent for the rest of that pad's life, with no error and nothing in a log.
+     *
+     * The undo is a report whose flag0 has BOTH bits clear (SDL's own comment: "Leaving emulated
+     * rumble bits off will restore audio haptics"). No other valid flag is set, so nothing else
+     * about the pad's state is touched. Mirrors `Ds5Feedback::audio_haptics_packet` on the desktop
+     * client, which is the same packet one transport over.
+     */
+    fun ds5AudioHapticsReport(model: Model): ByteArray = newDs5(model)
+
     fun ds5RumbleReport(model: Model, low: Int, high: Int): ByteArray = newDs5(model).also {
         it[1] = (DS5_FLAG0_COMPAT_VIBRATION or DS5_FLAG0_HAPTICS_SELECT).toByte()
         it[39] = DS5_FLAG2_VIBRATION2.toByte()
-        it[3] = amp8(high).toByte()
-        it[4] = amp8(low).toByte()
+        it[3] = wireAmplitudeToByte(high).toByte()
+        it[4] = wireAmplitudeToByte(low).toByte()
     }
 
     /**
@@ -324,17 +339,11 @@ object DsDevice {
         ByteArray(Model.DUALSHOCK4.outputSize).also {
             it[0] = 0x05
             it[1] = (DS4_FLAG0_MOTORS or DS4_FLAG0_LED).toByte()
-            it[4] = amp8(high).toByte()
-            it[5] = amp8(low).toByte()
+            it[4] = wireAmplitudeToByte(high).toByte()
+            it[5] = wireAmplitudeToByte(low).toByte()
             it[6] = r.toByte()
             it[7] = g.toByte()
             it[8] = b.toByte()
         }
 
-    // Wire u16 amplitude → motor byte; a nonzero command never collapses to 0 (parity with the
-    // vibrator path's toAmplitude).
-    private fun amp8(v16: Int): Int {
-        val a = (v16 ushr 8) and 0xFF
-        return if (v16 != 0 && a == 0) 1 else a
-    }
 }

clients/android/kit/src/main/kotlin/io/unom/punktfunk/kit/GamepadFeedback.kt

@@ -88,6 +88,9 @@ class GamepadFeedback(
         const val TAG_PLAYER_LEDS: Byte = 0x02
         const val TAG_TRIGGER: Byte = 0x03
         const val TAG_HID_RAW: Byte = 0x05
+
+        /** Sparse-log cadence for swallowed render failures — see [noteRenderFailure]. */
+        const val LOG_EVERY = 128L
     }
 
     /** One controller's rumble binding — VibratorManager (API 31+) OR the legacy single Vibrator (API 28–30). */
@@ -125,37 +128,51 @@ class GamepadFeedback(
     fun start() {
         running = true
         rumbleThread = Thread({
+            var failures = 0L
             while (running) {
                 val ev = NativeBridge.nativeNextRumble(handle)
-                if (ev < 0L) continue // timeout / closed
-                // ev bits 49..52 = wire pad index; bits 32..47 = backstop duration (ms);
-                // 16..31 = low; 0..15 = high. These are EFFECTIVE commands from the core's shared
-                // rumble policy engine — it owns every lease/staleness/close decision (uniform
-                // across all clients; the old 60 s legacy-host exposure is gone) and emits
-                // explicit zeros, so apply verbatim: (0, 0) = cancel, non-zero = one-shot for
-                // the backstop (the hardware net under a stalled poll thread).
-                val pad = ((ev ushr 49) and 0xFL).toInt()
-                val backstopMs = ((ev ushr 32) and 0xFFFF)
-                renderRumble(
-                    pad,
-                    ((ev ushr 16) and 0xFFFF).toInt(),
-                    (ev and 0xFFFF).toInt(),
-                    backstopMs,
-                )
+                // Layout + semantics live in `unpackRumbleEvent` (RumbleWire.kt), tested there
+                // against the Rust packer.
+                val cmd = unpackRumbleEvent(ev) ?: continue // timeout / closed
+                // Rendering is binder calls into the vibrator service, and every one of them can
+                // throw unchecked — DeadSystemRuntimeException when system_server goes down, and
+                // the ordinary RuntimeException a dying service wraps its RemoteException in.
+                // Unguarded, ONE of those killed this thread outright: `running` stayed true, so
+                // nothing noticed and nothing restarted it, and rumble was gone for the rest of
+                // the session. Losing a single command is recoverable; losing the loop is not.
+                runCatching {
+                    renderRumble(cmd.pad, cmd.low, cmd.high, cmd.backstopMs)
+                }.onFailure { failures = noteRenderFailure("rumble", it, failures) }
             }
         }, "pf-rumble").apply { isDaemon = true; start() }
 
         hidoutThread = Thread({
             // 128: the raw as-is passthrough events are [pad][kind tag][report kind][≤64 bytes].
             val buf = ByteBuffer.allocateDirect(128)
+            var failures = 0L
             while (running) {
                 val n = NativeBridge.nativeNextHidout(handle, buf)
                 if (n < 0) continue // timeout / closed
-                dispatchHidout(buf, n)
+                // Same hazard as the rumble loop above: lights/trigger rendering is binder and USB
+                // calls, and an unchecked throw here would silently end the rich-feedback plane.
+                runCatching { dispatchHidout(buf, n) }
+                    .onFailure { failures = noteRenderFailure("hidout", it, failures) }
             }
         }, "pf-hidout").apply { isDaemon = true; start() }
     }
 
+    /**
+     * Record a render failure the poll loop swallowed, and return the updated count. Logged on the
+     * first occurrence and sparsely after: a genuinely dead vibrator service fails on *every*
+     * command, which at a rumble plane's rate would bury the log.
+     */
+    private fun noteRenderFailure(plane: String, t: Throwable, seen: Long): Long {
+        if (seen == 0L || seen % LOG_EVERY == 0L) {
+            Log.w(TAG, "$plane render failed (#${seen + 1}) — command dropped, poll loop alive", t)
+        }
+        return seen + 1
+    }
+
     /** Idempotent. Stops + joins the poll threads (must complete before the router is released / handle freed). */
     fun stop() {
         running = false
@@ -264,12 +281,12 @@ class GamepadFeedback(
             return
         }
         val bind = rumbleBindFor(pad) ?: return
-        val lo = toAmplitude(low)
-        val hi = toAmplitude(high)
+        val lo = wireAmplitudeToByte(low)
+        val hi = wireAmplitudeToByte(high)
         val m = bind.vm
         if (m != null) {
             if (lo == 0 && hi == 0) {
-                m.cancel() // (0,0) = stop
+                runCatching { m.cancel() } // (0,0) = stop
                 return
             }
             val combo = CombinedVibration.startParallel()
@@ -294,7 +311,7 @@ class GamepadFeedback(
         // API 28–30 legacy single-motor path: blend both motors into one effect.
         val lv = bind.legacy ?: return
         if (lo == 0 && hi == 0) {
-            lv.cancel() // (0,0) = stop
+            runCatching { lv.cancel() } // (0,0) = stop
             return
         }
         val a = (lo * 0.8 + hi * 0.33).toInt().coerceIn(1, 255)
@@ -314,8 +331,8 @@ class GamepadFeedback(
      */
     private fun renderDeviceRumble(low: Int, high: Int, durationMs: Long) {
         val v = deviceVibrator ?: return
-        val lo = toAmplitude(low)
-        val hi = toAmplitude(high)
+        val lo = wireAmplitudeToByte(low)
+        val hi = wireAmplitudeToByte(high)
         if (lo == 0 && hi == 0) {
             runCatching { v.cancel() } // (0,0) = stop
             return
@@ -329,12 +346,6 @@ class GamepadFeedback(
         }
     }
 
-    // 0..0xFFFF → 1..255 (high byte); a nonzero motor never collapses to 0.
-    private fun toAmplitude(v16: Int): Int {
-        val a = (v16 ushr 8) and 0xFF
-        return if (v16 != 0 && a == 0) 1 else a
-    }
-
     // One-shot held for `durationMs` — the host's v2 TTL (renewed while the level holds), so it
     // self-terminates on a lost stop; cancel on zero. Floor the duration at 1 ms: `createOneShot`
     // throws IllegalArgumentException on a non-positive duration, and a lease can carry ttl_ms==0

clients/android/kit/src/main/kotlin/io/unom/punktfunk/kit/HidUsbLink.kt

@@ -14,8 +14,8 @@ import android.hardware.usb.UsbRequest
 import android.os.Build
 import android.util.Log
 import java.nio.ByteBuffer
-import java.util.concurrent.ConcurrentLinkedQueue
 import java.util.concurrent.TimeoutException
+import java.util.concurrent.atomic.AtomicBoolean
 
 /**
  * Generic USB transport for a client-captured HID controller — the device-agnostic half of what
@@ -81,17 +81,57 @@ class HidUsbLink(
 
     /** Pending OUT reports, submitted by the reader thread — only one thread may drive a
      *  connection's [UsbRequest]s ([UsbDeviceConnection.requestWait] returns ANY completed
-     *  request; a second waiter would steal the reader's completions). */
-    private val outQueue = ConcurrentLinkedQueue<ByteArray>()
+     *  request; a second waiter would steal the reader's completions). See [OutReportQueue] for
+     *  what gets discarded when it fills, and why that is not simply "the oldest". */
+    private val outQueue = OutReportQueue()
 
     private var reader: Thread? = null
     private var detachReceiver: BroadcastReceiver? = null
 
     @Volatile private var running = false
 
+    /** Latches on the first "this link is down" signal so [onClosed] fires exactly once, however
+     *  many of the racing detectors (detach broadcast, reader error streak, failed re-queue) see
+     *  it. Reset by [start]. */
+    private val down = AtomicBoolean(false)
+
     /** First attached matching device, or null. Does not need USB permission to enumerate. */
     fun findDevice(): UsbDevice? = usb.deviceList.values.firstOrNull(config.deviceMatch)
 
+    /**
+     * Open a SECOND connection to the same device, for a consumer that needs its own descriptor.
+     *
+     * **Not a convenience — a correctness requirement.** `UsbDeviceConnection.requestWait()`
+     * returns *any* completed request on that connection, and the same is true of the usbfs reap
+     * ioctl underneath it: two independent transfer engines sharing one descriptor steal each
+     * other's completions. This link's reader owns its connection exclusively (see the note on
+     * [outQueue]), so anything else driving transfers on this device — the isochronous audio
+     * renderer — must open its own.
+     *
+     * usbfs allows the same device to be opened many times, and claims are per (descriptor,
+     * interface), so a claim made on this connection does not conflict with one made on that.
+     *
+     * The caller owns the returned connection and must close it.
+     */
+    fun openAuxConnection(): UsbDeviceConnection? {
+        val dev = device ?: return null
+        return usb.openDevice(dev)
+    }
+
+    /**
+     * The open connection's usbfs file descriptor, or -1 when the link is not running.
+     *
+     * Handed to native code that drives interfaces this link deliberately does NOT claim — the
+     * pad's isochronous audio endpoint (see `pad_audio` on the native side), which Android's own
+     * USB API cannot reach because `UsbRequest` rejects anything that is not bulk or interrupt.
+     * usbfs claims are per interface, so a native claim of the audio interface leaves this link's
+     * HID claim untouched.
+     *
+     * **The borrower must stop using it before [stop] runs**: closing the connection while a
+     * transfer is in flight pulls the descriptor out from under the kernel.
+     */
+    val fileDescriptor: Int get() = connection?.fileDescriptor ?: -1
+
     /**
      * Claim [dev]'s controller interface(s) and start the read loop. The caller has already
      * obtained USB permission. Returns false when nothing could be claimed.
@@ -114,6 +154,7 @@ class HidUsbLink(
         connection = conn
         device = dev
         claims = claimed
+        down.set(false)
         running = true
         Log.i(
             config.tag,
@@ -134,10 +175,7 @@ class HidUsbLink(
                 val gone: UsbDevice? = intent.getParcelableExtra(UsbManager.EXTRA_DEVICE)
                 if (gone?.deviceName == dev.deviceName) {
                     Log.i(config.tag, "USB detached (${dev.deviceName})")
-                    if (running) {
-                        running = false
-                        onClosed()
-                    }
+                    linkDown()
                 }
             }
         }
@@ -221,6 +259,9 @@ class HidUsbLink(
         if (live.isEmpty()) {
             Log.e(config.tag, "no IN request could be queued")
             finishReader(claims)
+            // `start` already returned true, so without this the owner would sit waiting on a
+            // capture that never streams and never reports itself dead.
+            linkDown()
             return
         }
         val scratch = ByteArray(64)
@@ -295,10 +336,23 @@ class HidUsbLink(
         } finally {
             finishReader(claims)
         }
-        if (running) {
-            running = false
-            onClosed()
-        }
+        linkDown()
+    }
+
+    /**
+     * Report the link down, exactly once, from whichever detector noticed first — the detach
+     * broadcast (main thread) or the reader thread on its way out.
+     *
+     * This only *signals*; releasing the connection and the interfaces stays the owner's job, via
+     * the [stop] its `onClosed` handler calls. Previously nothing released them on this path: the
+     * detach receiver flipped a flag and fired the callback, so an unplug left the connection open,
+     * the interfaces claimed (the pad could not return to Android's own input stack) and the
+     * receiver still registered — and a re-plug overwrote the field holding it, leaking a receiver
+     * that stayed live for the process's lifetime.
+     */
+    private fun linkDown() {
+        running = false
+        if (down.compareAndSet(false, true)) onClosed()
     }
 
     private fun finishReader(claims: List<Claim>) {
@@ -314,28 +368,35 @@ class HidUsbLink(
      * Write one raw report to the device: kind 0 = output report (the active interface's
      * interrupt-OUT, else a `SET_REPORT(Output)` control transfer), kind 1 = feature report
      * (`SET_REPORT(Feature)`). [data] is the full report, id byte first, hidapi framing.
+     *
+     * [coalesce] tells the pending-OUT queue whether a newer report of the same kind may replace
+     * this one — [OutReportQueue.KEY_RUMBLE] for motor levels, the default [OutReportQueue.NO_COALESCE]
+     * for one-shots (lightbar, player LEDs, trigger effects) the sender will not repeat.
+     *
+     * Returns whether the report reached the device or is queued for it. A caller that is writing
+     * a **stop** needs this: a discarded stop has nothing behind it, so it must not be mistaken
+     * for one that landed.
      */
-    fun writeRaw(kind: Int, data: ByteArray) {
-        if (data.isEmpty()) return
-        when (kind) {
+    fun writeRaw(kind: Int, data: ByteArray, coalesce: Int = OutReportQueue.NO_COALESCE): Boolean {
+        if (data.isEmpty()) return false
+        return when (kind) {
             0 -> {
                 if ((activeClaim ?: claims.firstOrNull())?.outReq != null) {
-                    // Interrupt-OUT rides UsbRequests submitted by the reader thread. Bounded,
-                    // newest-wins: these are level-styled commands the sender re-sends anyway.
-                    while (outQueue.size >= 32) outQueue.poll()
-                    outQueue.offer(data)
+                    // Interrupt-OUT rides UsbRequests submitted by the reader thread.
+                    outQueue.offer(data, coalesce)
                 } else {
                     setReport(REPORT_TYPE_OUTPUT, data)
                 }
             }
             1 -> setReport(REPORT_TYPE_FEATURE, data)
+            else -> false
         }
     }
 
-    private fun setReport(type: Int, data: ByteArray) {
-        val conn = connection ?: return
-        val ifId = (activeClaim ?: claims.firstOrNull())?.iface?.id ?: return
-        sendReport(conn, ifId, type, data)
+    private fun setReport(type: Int, data: ByteArray): Boolean {
+        val conn = connection ?: return false
+        val ifId = (activeClaim ?: claims.firstOrNull())?.iface?.id ?: return false
+        return sendReport(conn, ifId, type, data)
     }
 
     /**
@@ -344,9 +405,8 @@ class HidUsbLink(
      * queue would never drain (e.g. a rumble stop before the interfaces release). Safe from any
      * thread: EP0 control transfers are independent of the reader's `requestWait`.
      */
-    fun writeControl(data: ByteArray) {
-        if (data.isNotEmpty()) setReport(REPORT_TYPE_OUTPUT, data)
-    }
+    fun writeControl(data: ByteArray): Boolean =
+        data.isNotEmpty() && setReport(REPORT_TYPE_OUTPUT, data)
 
     private fun sendKeepAlive(conn: UsbDeviceConnection, ifaceId: Int) {
         for (f in config.keepAliveFeatures) sendReport(conn, ifaceId, REPORT_TYPE_FEATURE, f)
@@ -358,27 +418,48 @@ class HidUsbLink(
      * "unnumbered" (id 0 in wValue, id byte stripped from the payload). EP0 is independent of
      * the interrupt endpoints, so this is safe alongside the reader thread's requestWait.
      */
-    private fun sendReport(conn: UsbDeviceConnection, ifaceId: Int, type: Int, data: ByteArray) {
+    private fun sendReport(
+        conn: UsbDeviceConnection,
+        ifaceId: Int,
+        type: Int,
+        data: ByteArray,
+    ): Boolean {
         val id = data[0].toInt() and 0xFF
         val payload = if (id == 0) data.copyOfRange(1, data.size) else data
-        conn.controlTransfer(
-            0x21, // host→device, class, interface
-            0x09, // SET_REPORT
-            (type shl 8) or id,
-            ifaceId,
-            payload,
-            payload.size,
-            WRITE_TIMEOUT_MS,
-        )
+        // controlTransfer returns the byte count, or a negative value on failure — a failed write
+        // must be reported as such, not swallowed (a dropped rumble stop has nothing behind it).
+        val n = runCatching {
+            conn.controlTransfer(
+                0x21, // host→device, class, interface
+                0x09, // SET_REPORT
+                (type shl 8) or id,
+                ifaceId,
+                payload,
+                payload.size,
+                WRITE_TIMEOUT_MS,
+            )
+        }.getOrDefault(-1)
+        return n >= 0
     }
 
-    /** Stop the read loop and release the interfaces. Idempotent; does not fire [onClosed]. */
+    /**
+     * Stop the read loop and release the interfaces. Idempotent; does not fire [onClosed].
+     *
+     * Safe to call from the `onClosed` handler itself — that is how an unplug now gets cleaned up,
+     * and it arrives on the reader thread, which must not try to join itself.
+     */
     fun stop() {
         running = false
+        // Claim the down-latch so the reader's own exit does not report a close the owner asked for.
+        down.set(true)
         detachReceiver?.let { runCatching { context.unregisterReceiver(it) } }
         detachReceiver = null
-        runCatching { reader?.join(1000) }
-        reader = null
+        if (reader !== Thread.currentThread()) {
+            runCatching { reader?.join(1000) }
+            // Only forget the thread once it is actually gone: clearing it while it still runs
+            // would let a later stop() skip the join and free the connection under it.
+            reader = null
+        }
         outQueue.clear()
         activeClaim = null
         for (c in claims) runCatching { connection?.releaseInterface(c.iface) }

clients/android/kit/src/main/kotlin/io/unom/punktfunk/kit/NativeBridge.kt

@@ -69,6 +69,10 @@ object NativeBridge {
          *  list and trust store show for it, same convention as [nativePair]'s `name`. `null`/blank ⇒
          *  the host falls back to a fingerprint-derived "device abcd1234" label. */
         deviceName: String?,
+        /** Advertise `CLIENT_CAP_PAD_AUDIO` — the SESSION-level negotiation for the 0xD1 per-pad
+         *  DualSense plane. Without it the host never sets `HOST_CAP_PAD_AUDIO` and emits nothing,
+         *  so a captured pad's own render capabilities would have nothing to gate. */
+        padAudioOk: Boolean,
     ): Long
 
     /** 64-hex SHA-256 of the cert the host presented on [handle]; valid after a successful connect. */
@@ -332,6 +336,46 @@ object NativeBridge {
      */
     external fun nativeSetMicMuted(handle: Long, muted: Boolean)
 
+    /**
+     * Start tier-A DualSense pad audio: render the host's `0xD1` streams on the pad's own
+     * 4-channel USB audio device.
+     *
+     * [fd] is an open [android.hardware.usb.UsbDeviceConnection]'s file descriptor. Native code
+     * **borrows** it — it claims the pad's audio interface through usbfs (which leaves any HID
+     * claim on the same device alone) and never closes the descriptor. The caller must keep the
+     * connection open until [nativeStopPadAudio] returns.
+     *
+     * This also declares the pad's render capability to the host; without it no `0xD1` is sent.
+     *
+     * Returns false when there is nothing to render. A kernel that refuses the interface claim is
+     * NOT reported here — the renderer discovers that on its own thread and the session simply
+     * carries on without tier A, because some OEM kernels refuse and no app-side fix exists.
+     */
+    external fun nativeStartPadAudio(
+        handle: Long,
+        pad: Int,
+        fd: Int,
+        haptics: Boolean,
+        speaker: Boolean,
+    ): Boolean
+
+    /**
+     * Stop tier-A pad audio and join its render thread, and hand the pad back to wire rumble.
+     *
+     * Returns only once the thread is joined — so the `UsbDeviceConnection` may be closed as soon
+     * as this returns, and not before.
+     */
+    external fun nativeStopPadAudio(handle: Long, pad: Int)
+
+    /**
+     * Drive the pad with a test tone through the real render path — no host, no session.
+     *
+     * [fd] must come from a connection **nothing else is driving transfers on**: two engines on
+     * one usbfs descriptor reap each other's completions. Blocks for roughly [seconds]; run it off
+     * the main thread. Returns sample frames written, or negative on failure.
+     */
+    external fun nativePadAudioSelfTest(fd: Int, seconds: Int, hz: Int): Int
+
     /**
      * Is a mic capture actually RUNNING — i.e. did [nativeStartMic] open a stream, and has
      * [nativeStopMic] not been called since? Offer the in-stream mute control on THIS rather than

clients/android/kit/src/main/kotlin/io/unom/punktfunk/kit/OutReportQueue.kt

@@ -0,0 +1,89 @@
+package io.unom.punktfunk.kit
+
+/**
+ * The pending interrupt-OUT reports for a captured controller: a bounded FIFO whose overflow
+ * policy knows which reports may be thrown away and which may not.
+ *
+ * The queue exists because only one thread may drive a connection's `UsbRequest`s, so writes from
+ * the feedback threads are handed to the reader thread rather than submitted directly. It has to
+ * be bounded — a stalled or unplugged device would otherwise grow it without limit — and the
+ * question is what to discard when it fills.
+ *
+ * The old policy was "newest wins": drop from the head until there is room. That is right for
+ * rumble, which is *level-styled* — the host re-sends it continuously, so a dropped frame is
+ * replaced milliseconds later and nothing is permanently lost. It is wrong for everything else.
+ * A lightbar colour, a player-LED mask and an adaptive-trigger effect are **one-shots**: the host
+ * sends them on change and never repeats them. Dropping one leaves the pad wrong until the next
+ * time that value happens to change, which may be never.
+ *
+ * So eviction is driven by an explicit [key] supplied by the caller, not by inspecting the bytes.
+ * That distinction cannot be recovered from the report itself: every DualSense output report
+ * carries the *same* report id and differs only in its `valid_flag` bytes, so an id-keyed policy
+ * would happily let a rumble supersede a lightbar — the very bug this replaces, relocated.
+ *
+ * Two rules:
+ *  - A report offered with a coalescing key **replaces** the pending report with that key, in
+ *    place. A burst of rumble collapses to its latest value and never displaces anything else.
+ *  - Only when the queue is full does anything get dropped, and then the oldest *coalescable*
+ *    report goes first. A one-shot is discarded only if the queue is full of nothing but
+ *    one-shots — which needs [cap] distinct one-shots outstanding, far beyond what a real pad
+ *    produces.
+ *
+ * Thread-safe: offered by the feedback threads, drained by the reader thread.
+ */
+internal class OutReportQueue(private val cap: Int = CAP) {
+    private class Entry(val key: Int, val data: ByteArray)
+
+    private val items = ArrayDeque<Entry>()
+
+    /**
+     * Queue [data] for submission. [key] is [NO_COALESCE] for a one-shot, or a caller-chosen
+     * constant identifying a level-styled stream whose newer values supersede older ones.
+     *
+     * Returns false only if the report had to be dropped outright — the caller can then treat the
+     * write as failed rather than assuming it is on its way.
+     */
+    fun offer(data: ByteArray, key: Int = NO_COALESCE): Boolean = synchronized(items) {
+        if (key != NO_COALESCE) {
+            val at = items.indexOfFirst { it.key == key }
+            if (at >= 0) {
+                // Supersede in place: keeping the queue position stops a fast rumble stream from
+                // repeatedly jumping the one-shots queued ahead of it.
+                items[at] = Entry(key, data)
+                return true
+            }
+        }
+        if (items.size >= cap) {
+            val victim = items.indexOfFirst { it.key != NO_COALESCE }
+            if (victim >= 0) {
+                items.removeAt(victim)
+            } else if (key != NO_COALESCE) {
+                // Nothing coalescable to sacrifice and this report is itself replaceable — drop it
+                // rather than a one-shot that will never come again.
+                return false
+            } else {
+                items.removeFirst()
+            }
+        }
+        items.addLast(Entry(key, data))
+        return true
+    }
+
+    /** The next report to submit, or null when nothing is pending. */
+    fun poll(): ByteArray? = synchronized(items) { items.removeFirstOrNull()?.data }
+
+    fun clear() = synchronized(items) { items.clear() }
+
+    val size: Int get() = synchronized(items) { items.size }
+
+    companion object {
+        /** This report is a one-shot: never superseded, evicted only as a last resort. */
+        const val NO_COALESCE = 0
+
+        /** Motor levels — re-sent continuously, so only the newest is worth keeping. */
+        const val KEY_RUMBLE = 1
+
+        /** Deep enough to absorb a burst, small enough that a stalled device cannot bloat us. */
+        const val CAP = 32
+    }
+}

clients/android/kit/src/main/kotlin/io/unom/punktfunk/kit/RumbleWire.kt

@@ -0,0 +1,47 @@
+package io.unom.punktfunk.kit
+
+/**
+ * The two conversions every rumble path in this module needs, in one place.
+ *
+ * Both used to be transcribed per call site: [wireAmplitudeToByte] existed twice, byte-identical,
+ * in `GamepadFeedback` and `DsDevice`; [unpackRumbleEvent] was inline bit-shifting in the poll loop
+ * with no test on either side of the JNI boundary. Neither is complicated — which is exactly why a
+ * silent divergence between copies would have been hard to notice.
+ */
+
+/**
+ * Wire amplitude (`0..0xFFFF`) → an 8-bit motor/vibrator level.
+ *
+ * The high byte, except that a **nonzero command never collapses to zero**: anything below 0x0100
+ * would otherwise round to silence, turning a weak-but-real rumble into no rumble at all. 1 is
+ * imperceptibly light, but it moves.
+ */
+internal fun wireAmplitudeToByte(v16: Int): Int {
+    val a = (v16 ushr 8) and 0xFF
+    return if (v16 != 0 && a == 0) 1 else a
+}
+
+/** One effective rumble command, as packed by the native side's `nativeNextRumble`. */
+internal data class RumbleCmd(val pad: Int, val low: Int, val high: Int, val backstopMs: Long)
+
+/**
+ * Unpack `NativeBridge.nativeNextRumble`'s `jlong`, or null for the timeout/closed sentinel.
+ *
+ * Layout, mirroring `clients/android/native/src/feedback.rs::pack_rumble`:
+ * bits 49..52 = wire pad index, 32..47 = backstop duration (ms), 16..31 = low, 0..15 = high.
+ * The pad field is 4 bits because `punktfunk_core::input::MAX_PADS` is 16 — the Rust side has a
+ * compile-time assertion tying the two together, so this can't silently start truncating.
+ *
+ * These are EFFECTIVE commands from the core's shared rumble policy engine: it owns every
+ * lease/staleness/close decision and emits explicit zeros, so apply them verbatim —
+ * `(0, 0)` = cancel, non-zero = one-shot for the backstop.
+ */
+internal fun unpackRumbleEvent(ev: Long): RumbleCmd? {
+    if (ev < 0L) return null // timeout / closed
+    return RumbleCmd(
+        pad = ((ev ushr 49) and 0xFL).toInt(),
+        low = ((ev ushr 16) and 0xFFFF).toInt(),
+        high = (ev and 0xFFFF).toInt(),
+        backstopMs = (ev ushr 32) and 0xFFFF,
+    )
+}

clients/android/kit/src/main/kotlin/io/unom/punktfunk/kit/Sc2Capture.kt

@@ -273,10 +273,20 @@ class Sc2Capture(
 
     private fun onLinkClosed() {
         Log.i(TAG, "SC2 link closed (unplug / power-off)")
+        // Both transports share this callback, so read which one was live BEFORE clearing it —
+        // releasing the other would tear down a link that never dropped.
+        val dropped = activeLink
         activeLink = LINK_NONE
         dongleLink = false
         releaseSlot()
         releaseUiKeys()
+        // Release the transport too — see the note in DsCapture.onLinkClosed. The Puck makes this
+        // worse than a single leak: it is the pad that gets power-cycled, so the same process can
+        // round-trip a link many times in one session.
+        when (dropped) {
+            LINK_USB -> usb.stop()
+            LINK_BLE -> ble.stop()
+        }
         onActiveChanged?.invoke(false)
     }
 

clients/android/kit/src/main/kotlin/io/unom/punktfunk/kit/library/Library.kt

@@ -127,8 +127,14 @@ object LibraryClient {
  * An OkHttpClient that presents the paired client cert and pins the host's self-signed cert by
  * SHA-256(DER) — reused for BOTH the library fetch and the cover-art loads (so a paired client
  * reaches the host's own art proxy). The pinning trust manager trusts the host by fingerprint and
- * defers to normal public trust for any other origin (an external CDN URL); the hostname verifier
- * accepts the pinned host (whose self-signed cert has no matching SAN) and defers otherwise.
+ * defers to normal public trust for any other origin (an external CDN URL).
+ *
+ * The two checks are only sound TOGETHER, and the composition is the point: the trust manager
+ * cannot fail closed on its own (it has no hostname, so it must let a CDN chain through), so the
+ * hostname verifier is what makes the pinned host pin-only. Loosen either and a publicly-trusted
+ * certificate for any name is accepted for the host — which is exactly what 2026-08-05 review M-2
+ * found. The host's own cert is self-signed with no matching SAN, so it can never satisfy the
+ * default verifier; the pin is its only credential, on purpose.
  */
 fun mtlsHttpClient(certPem: String, keyPem: String, host: String, fpHex: String): OkHttpClient {
     val clientCert = CertificateFactory.getInstance("X.509")
@@ -162,7 +168,26 @@ fun mtlsHttpClient(certPem: String, keyPem: String, host: String, fpHex: String)
 
     val defaultVerifier = HttpsURLConnection.getDefaultHostnameVerifier()
     val verifier = HostnameVerifier { hostname, session ->
-        hostname == host || defaultVerifier.verify(hostname, session)
+        if (hostname == host) {
+            // The PINNED host fails closed: only the pinned leaf is acceptable for this name.
+            //
+            // This used to be a bare `hostname == host`, which composed with the trust manager's
+            // system-CA fall-through into "any publicly-trusted certificate, for any name, is
+            // accepted for the pinned host" — the pin was decorative (2026-08-05 review M-2). A
+            // MITM with any free CA-issued cert intercepted the connection, received the client's
+            // mTLS IDENTITY certificate, and served attacker-chosen library JSON and art URLs.
+            // The Rust (`pf-client-core`) and Apple (`ClientTLS`) paths already fail closed here;
+            // only Android did not.
+            try {
+                sha256Hex((session.peerCertificates.firstOrNull() as? X509Certificate)?.encoded ?: return@HostnameVerifier false) == pinned
+            } catch (_: Exception) {
+                false
+            }
+        } else {
+            // Any other origin (an external CDN art URL) is ordinary public trust: the system
+            // trust manager validated the chain, and this checks the name against it.
+            defaultVerifier.verify(hostname, session)
+        }
     }
 
     return OkHttpClient.Builder()

clients/android/kit/src/test/kotlin/io/unom/punktfunk/kit/OutReportQueueTest.kt

@@ -0,0 +1,102 @@
+package io.unom.punktfunk.kit
+
+import org.junit.Assert.assertArrayEquals
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertNull
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+/**
+ * The pending-OUT queue's overflow policy. What is being pinned here is the distinction the old
+ * "drop from the head until there is room" policy did not make: rumble is re-sent continuously and
+ * may be thrown away, while a lightbar/player-LED/trigger report is sent once and never repeated.
+ */
+class OutReportQueueTest {
+    /** A report carrying a 0..255 marker so a test can tell which one came back out. */
+    private fun report(marker: Int) = byteArrayOf(0x02, marker.toByte())
+
+    // Masked: the marker rides in a Byte, and Byte.toInt() sign-extends.
+    private fun drain(q: OutReportQueue): List<Int> =
+        generateSequence { q.poll() }.map { it[1].toInt() and 0xFF }.toList()
+
+    @Test
+    fun `rumble supersedes the pending rumble instead of queueing another`() {
+        val q = OutReportQueue()
+        assertTrue(q.offer(report(1), OutReportQueue.KEY_RUMBLE))
+        assertTrue(q.offer(report(2), OutReportQueue.KEY_RUMBLE))
+        assertTrue(q.offer(report(3), OutReportQueue.KEY_RUMBLE))
+        assertEquals("a rumble burst must collapse to one entry", 1, q.size)
+        assertArrayEquals(report(3), q.poll())
+        assertNull(q.poll())
+    }
+
+    @Test
+    fun `superseding keeps the queue position so a rumble stream cannot jump one-shots`() {
+        val q = OutReportQueue()
+        q.offer(report(1), OutReportQueue.KEY_RUMBLE)
+        q.offer(report(10)) // a one-shot queued behind it
+        q.offer(report(2), OutReportQueue.KEY_RUMBLE)
+        // The newer rumble takes the OLD rumble's slot, so the one-shot does not get starved
+        // behind an endlessly-renewed entry.
+        assertEquals(listOf(2, 10), drain(q))
+    }
+
+    @Test
+    fun `a full queue sacrifices rumble, never a one-shot`() {
+        val q = OutReportQueue(cap = 4)
+        q.offer(report(1), OutReportQueue.KEY_RUMBLE)
+        q.offer(report(10))
+        q.offer(report(11))
+        q.offer(report(12))
+        assertEquals(4, q.size)
+        // Full. The old policy dropped the head — here that is a rumble, but only by luck of
+        // ordering; what matters is that the one-shots all survive.
+        assertTrue(q.offer(report(13)))
+        assertEquals(listOf(10, 11, 12, 13), drain(q))
+    }
+
+    @Test
+    fun `the one-shot the host never repeats survives a rumble storm`() {
+        val q = OutReportQueue(cap = 4)
+        // The exact regression: a lightbar colour queued once, then a flood of rumble. Under the
+        // old newest-wins eviction the colour was dropped from the head and never came back,
+        // leaving the pad lit wrong until the value next happened to change.
+        q.offer(report(200)) // lightbar
+        repeat(50) { q.offer(report(it), OutReportQueue.KEY_RUMBLE) }
+        val out = drain(q)
+        assertTrue("the lightbar report must still be queued, got $out", out.contains(200))
+        assertEquals("rumble must not have accumulated", listOf(200, 49), out)
+    }
+
+    @Test
+    fun `a queue full of one-shots refuses a rumble rather than dropping one`() {
+        val q = OutReportQueue(cap = 2)
+        q.offer(report(10))
+        q.offer(report(11))
+        assertFalse(
+            "with nothing coalescable to sacrifice, the replaceable report yields",
+            q.offer(report(1), OutReportQueue.KEY_RUMBLE),
+        )
+        assertEquals(listOf(10, 11), drain(q))
+    }
+
+    @Test
+    fun `only a queue of nothing but one-shots drops one, and it is the oldest`() {
+        val q = OutReportQueue(cap = 2)
+        q.offer(report(10))
+        q.offer(report(11))
+        assertTrue(q.offer(report(12)))
+        assertEquals(listOf(11, 12), drain(q))
+    }
+
+    @Test
+    fun `clear empties the queue`() {
+        val q = OutReportQueue()
+        q.offer(report(1), OutReportQueue.KEY_RUMBLE)
+        q.offer(report(10))
+        q.clear()
+        assertEquals(0, q.size)
+        assertNull(q.poll())
+    }
+}

clients/android/kit/src/test/kotlin/io/unom/punktfunk/kit/RumbleWireTest.kt

@@ -0,0 +1,79 @@
+package io.unom.punktfunk.kit
+
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNotEquals
+import org.junit.Assert.assertNull
+import org.junit.Test
+
+/**
+ * The Kotlin half of the rumble JNI boundary. The Rust half is pinned by `pack_rumble_tests` in
+ * `clients/android/native/src/feedback.rs`; the two suites describe the same layout from opposite
+ * sides, which is the only thing that catches one of them drifting.
+ */
+class RumbleWireTest {
+
+    /** `pack_rumble` from the native side, transcribed — the packer these tests unpack. */
+    private fun pack(pad: Int, low: Int, high: Int, backstopMs: Int): Long =
+        ((pad and 0xF).toLong() shl 49) or
+            ((backstopMs.coerceAtMost(0xFFFF)).toLong() shl 32) or
+            (low.toLong() shl 16) or
+            high.toLong()
+
+    @Test
+    fun `every field round-trips at its extremes`() {
+        val cases = listOf(
+            listOf(0, 0, 0, 0),
+            listOf(15, 0xFFFF, 0xFFFF, 0xFFFF),
+            listOf(1, 0x1234, 0x5678, 500),
+            listOf(7, 0, 0xFFFF, 2000),
+        )
+        for ((pad, low, high, backstop) in cases) {
+            val cmd = unpackRumbleEvent(pack(pad, low, high, backstop))!!
+            assertEquals("pad", pad, cmd.pad)
+            assertEquals("low", low, cmd.low)
+            assertEquals("high", high, cmd.high)
+            assertEquals("backstop", backstop.toLong(), cmd.backstopMs)
+        }
+    }
+
+    /** MAX_PADS is 16, so all 16 indices must survive the 4-bit field without aliasing. */
+    @Test
+    fun `all sixteen pad indices are distinct`() {
+        val seen = (0 until 16).map { unpackRumbleEvent(pack(it, 1, 2, 3))!!.pad }
+        assertEquals((0 until 16).toList(), seen)
+    }
+
+    @Test
+    fun `the negative sentinel is not a command`() {
+        assertNull(unpackRumbleEvent(-1L))
+        assertNull(unpackRumbleEvent(Long.MIN_VALUE))
+    }
+
+    @Test
+    fun `a stop is distinguishable from a hold`() {
+        val stop = unpackRumbleEvent(pack(2, 0, 0, 0))!!
+        val hold = unpackRumbleEvent(pack(2, 0x8000, 0x8000, 500))!!
+        assertEquals(0, stop.low)
+        assertEquals(0, stop.high)
+        assertNotEquals(stop, hold)
+    }
+
+    // --- wireAmplitudeToByte (was two byte-identical private copies) ---
+
+    @Test
+    fun `amplitude takes the high byte`() {
+        assertEquals(0xFF, wireAmplitudeToByte(0xFFFF))
+        assertEquals(0x80, wireAmplitudeToByte(0x8000))
+        assertEquals(0x12, wireAmplitudeToByte(0x1234))
+    }
+
+    @Test
+    fun `zero stays silent but a weak nonzero never does`() {
+        assertEquals("only a real zero may render as silence", 0, wireAmplitudeToByte(0))
+        // Everything below 0x0100 has a zero high byte — without the floor these all vanish.
+        for (v in listOf(1, 0x0042, 0x00FF)) {
+            assertEquals("wire $v collapsed to silence", 1, wireAmplitudeToByte(v))
+        }
+        assertEquals(1, wireAmplitudeToByte(0x0100)) // first value that reaches 1 on its own
+    }
+}

clients/android/native/Cargo.toml

@@ -64,6 +64,14 @@ libc = "0.2"
 # host + Linux client use. audiopus_sys vendors libopus (pure C) and builds it static via cmake —
 # the cargo-ndk build sets LIBOPUS_STATIC=1/LIBOPUS_NO_PKG=1 so it links the bundled lib, not the host's.
 opus = "0.3"
+# Tier-A pad audio (WP9). Android's audio framework denylists the DualSense's output by VID/PID,
+# so the pad's isochronous endpoint is driven directly on the fd `UsbDeviceConnection` hands over.
+# Our own crates, developed openly because the hole they fill — isochronous USB in Rust — is an
+# ecosystem-wide one: https://github.com/unom-io/usbfs-iso
+# Pinned by revision rather than floating: this is a transport under a real-time deadline and it
+# should move when we choose to. Becomes a plain version dependency once the crates are published.
+uac-host = { git = "https://github.com/unom-io/usbfs-iso", rev = "f3de1fd62cec271d07f45664dc464f23e423e721" }
+usbfs-iso = { git = "https://github.com/unom-io/usbfs-iso", rev = "f3de1fd62cec271d07f45664dc464f23e423e721" }
 
 [lints]
 workspace = true

clients/android/native/src/decode/async_loop.rs

@@ -28,6 +28,76 @@ use super::{
     NO_VIDEO_RETRY, PENDING_SPLIT_CAP,
 };
 
+/// How long a flagged AU waits for the host's 0xCF timing before being logged unattributed.
+/// Comfortably longer than the round the host takes to report, short enough that the line still
+/// lands near the event in the log.
+const SPIKE_ATTRIBUTE_WAIT_NS: i64 = 500_000_000;
+
+/// Bound on AUs awaiting attribution — a stream that spikes constantly must not grow this.
+const SPIKE_WATCH_CAP: usize = 64;
+
+/// One receipt-latency excursion, held until the host's own timing for the same AU arrives.
+///
+/// The point of this record is attribution. A window maximum cannot say WHERE a 90 ms frame
+/// spent its time — the per-stage maxima in a window are generally different frames — so the
+/// stage split has to be captured per AU, for the offending AU.
+struct SpikeWatch {
+    pts_ns: u64,
+    /// Capture → reassembled, skew-corrected: the host pipeline plus the wire.
+    hostnet_us: u64,
+    au_len: usize,
+    /// Since the previous AU was reassembled — separates "this frame was slow" from "the
+    /// stream stalled and then burst", which look identical in a latency percentile.
+    gap_us: u64,
+    idx: u32,
+    seen_mono: i64,
+}
+
+impl SpikeWatch {
+    /// `host_us` = the host's own capture→submit time for this AU (0xCF), or `None` when the
+    /// host never reported it. `net` is the remainder: wire + reassembly.
+    fn log(&self, host_us: Option<u64>) {
+        log::warn!(
+            target: "pf.spike",
+            "idx={} hostnetMs={:.1} hostMs={} netMs={} gapMs={:.1} bytes={}",
+            self.idx,
+            self.hostnet_us as f64 / 1000.0,
+            host_us.map_or("?".into(), |h| format!("{:.1}", h as f64 / 1000.0)),
+            host_us.map_or("?".into(), |h| format!(
+                "{:.1}",
+                self.hostnet_us.saturating_sub(h) as f64 / 1000.0
+            )),
+            self.gap_us as f64 / 1000.0,
+            self.au_len,
+        );
+    }
+}
+
+/// `debug.punktfunk.spike_ms` (1..=2000): log a per-AU stage breakdown for every receipt latency
+/// at or above this. Unset = off, so the instrument costs nothing until someone asks for it.
+fn spike_threshold_us() -> Option<u64> {
+    let mut buf = [0u8; 92]; // PROP_VALUE_MAX
+                             // SAFETY: __system_property_get with a valid name + PROP_VALUE_MAX buffer is always safe.
+    let n = unsafe {
+        libc::__system_property_get(
+            c"debug.punktfunk.spike_ms".as_ptr(),
+            buf.as_mut_ptr().cast(),
+        )
+    };
+    if n > 0 {
+        if let Ok(ms) = std::str::from_utf8(&buf[..n as usize])
+            .unwrap_or("")
+            .trim()
+            .parse::<u64>()
+        {
+            if (1..=2_000).contains(&ms) {
+                return Some(ms * 1_000);
+            }
+        }
+    }
+    None
+}
+
 /// One decoded output buffer ready to release: its codec buffer index + the pts the codec echoed
 /// (from the output callback's `BufferInfo`), used to pair the `decode` HUD stat, and the
 /// wall-clock instant the output callback fired — the spec's `decoded` point ("decoder output
@@ -584,6 +654,14 @@ fn feeder_loop(
     // Last logged phase-lock ACK (the host's applied capture hold, from the 0xCF tail) — logged
     // on change so `adb logcat -s pf.phase` shows the closed loop working (or not) at a glance.
     let mut last_phase_ack: Option<i32> = None;
+    // Latency-excursion watch (`debug.punktfunk.spike_ms`). Read once per stream: this is a
+    // field instrument, armed by setprop + reconnect, and off by default.
+    let spike_thresh_us = spike_threshold_us();
+    if let Some(t) = spike_thresh_us {
+        log::info!("decode: spike watch armed at {} ms (pf.spike)", t / 1000);
+    }
+    let mut spike_watch: VecDeque<SpikeWatch> = VecDeque::new();
+    let mut last_recv_mono: Option<i64> = None;
     while !shutdown.load(Ordering::Relaxed) {
         match client.next_frame(Duration::from_millis(5)) {
             Ok(frame) => {
@@ -599,6 +677,44 @@ fn feeder_loop(
                 // Park the receipt stamp (keyed by the pts the codec echoes) whenever the `decode`
                 // stage is consumed: the HUD, or the ABR decode signal (`measure_decode`). The
                 // HUD-only `received` point + host/network split stay gated on the overlay.
+                // The receipt latency is needed by the always-on spike watch below, so it is
+                // computed for every complete AU rather than only when the HUD is up.
+                let spike_lat_us = if frame.complete {
+                    let received_ns = if frame.received_ns > 0 {
+                        frame.received_ns as i128
+                    } else {
+                        now_realtime_ns()
+                    };
+                    let off = clock_offset.load(Ordering::Relaxed) as i128;
+                    let lat_ns = received_ns + off - frame.pts_ns as i128;
+                    (lat_ns > 0 && lat_ns < 10_000_000_000).then_some((lat_ns / 1000) as u64)
+                } else {
+                    None
+                };
+                if let (Some(thresh_us), Some(lat_us)) = (spike_thresh_us, spike_lat_us) {
+                    let now_mono = now_monotonic_ns();
+                    let gap_us = last_recv_mono
+                        .map(|p| ((now_mono - p) / 1000) as u64)
+                        .unwrap_or(0);
+                    last_recv_mono = Some(now_mono);
+                    if lat_us >= thresh_us {
+                        let au_len = frame.part.map_or(0, |p| p.offset as usize) + frame.data.len();
+                        // Held for the host's 0xCF timing for this pts, which is what splits the
+                        // excursion into host pipeline vs wire — the whole point. Emitted
+                        // unattributed if that never arrives (see the drain below).
+                        spike_watch.push_back(SpikeWatch {
+                            pts_ns: frame.pts_ns,
+                            hostnet_us: lat_us,
+                            au_len,
+                            gap_us,
+                            idx: frame.frame_index,
+                            seen_mono: now_mono,
+                        });
+                        if spike_watch.len() > SPIKE_WATCH_CAP {
+                            spike_watch.pop_front();
+                        }
+                    }
+                }
                 if (stats.enabled() || measure_decode) && frame.complete {
                     // Core reassembly-completion stamp (ABI v9), NOT the pull instant: stamping
                     // here would fold the hand-off queue wait into the network latency figure
@@ -632,28 +748,47 @@ fn feeder_loop(
                                 pending_split.pop_front();
                             }
                         }
-                        while let Ok(t) = client.next_host_timing(Duration::ZERO) {
-                            // Phase-lock closed-loop readout: the host's applied hold rides the
-                            // 0xCF tail; log transitions (~1 Hz worst case — the host updates it
-                            // once a second). None = a host without the tail (pre-phase-lock).
-                            if t.applied_phase_ns != last_phase_ack {
-                                log::info!(
-                                    target: "pf.phase",
-                                    "host applied_phase={:?}us",
-                                    t.applied_phase_ns.map(|n| n / 1000)
-                                );
-                                last_phase_ack = t.applied_phase_ns;
-                            }
-                            if let Some(i) = pending_split.iter().position(|&(p, _)| p == t.pts_ns)
-                            {
-                                let (_, hostnet_us) = pending_split.remove(i).unwrap();
-                                stats.note_host_split(
-                                    t.host_us as u64,
-                                    hostnet_us.saturating_sub(t.host_us as u64),
-                                );
-                            }
+                    }
+                }
+                // The 0xCF drain is OUTSIDE the HUD gate: it carries the host's own pipeline time
+                // per AU, which is what attributes a latency excursion to the host or the wire,
+                // and the phase-lock ack, which had no business being invisible with the HUD down.
+                while let Ok(t) = client.next_host_timing(Duration::ZERO) {
+                    // Phase-lock closed-loop readout: the host's applied hold rides the
+                    // 0xCF tail; log transitions (~1 Hz worst case — the host updates it
+                    // once a second). None = a host without the tail (pre-phase-lock).
+                    if t.applied_phase_ns != last_phase_ack {
+                        log::info!(
+                            target: "pf.phase",
+                            "host applied_phase={:?}us",
+                            t.applied_phase_ns.map(|n| n / 1000)
+                        );
+                        last_phase_ack = t.applied_phase_ns;
+                    }
+                    if stats.enabled() {
+                        if let Some(i) = pending_split.iter().position(|&(p, _)| p == t.pts_ns) {
+                            let (_, hostnet_us) = pending_split.remove(i).unwrap();
+                            stats.note_host_split(
+                                t.host_us as u64,
+                                hostnet_us.saturating_sub(t.host_us as u64),
+                            );
                         }
                     }
+                    if let Some(i) = spike_watch.iter().position(|w| w.pts_ns == t.pts_ns) {
+                        let w = spike_watch.remove(i).unwrap();
+                        w.log(Some(t.host_us as u64));
+                    }
+                }
+                // Anything the host never reported on still gets logged, unattributed, rather
+                // than silently dropped — an old host has no 0xCF tail at all.
+                let now_mono = now_monotonic_ns();
+                while spike_watch
+                    .front()
+                    .is_some_and(|w| now_mono - w.seen_mono > SPIKE_ATTRIBUTE_WAIT_NS)
+                {
+                    if let Some(w) = spike_watch.pop_front() {
+                        w.log(None);
+                    }
                 }
                 if ev_tx.send(DecodeEvent::Au(frame, gap)).is_err() {
                     break; // the decode loop is gone

clients/android/native/src/decode/display.rs

@@ -185,7 +185,7 @@ unsafe extern "C" fn on_frame_rendered(
     let display_us = paired.and_then(|(d, _)| clamp(displayed_ns - d));
     let latch_us = paired.and_then(|(_, r)| clamp(displayed_ns - r));
     // Always-on half: the presenter's pf-present line reads these with the HUD off.
-    t.meter.note_latch(latch_us);
+    t.meter.note_latch(latch_us, system_nano);
     if !t.stats.enabled() {
         return; // HUD hidden — skip the skew math + the stats lock
     }

clients/android/native/src/decode/presenter.rs

@@ -22,7 +22,7 @@
 
 use ndk::media::media_codec::MediaCodec;
 use std::collections::VecDeque;
-use std::sync::atomic::{AtomicBool, AtomicI32, Ordering};
+use std::sync::atomic::{AtomicBool, AtomicI32, AtomicI64, Ordering};
 use std::sync::Mutex;
 use std::time::Instant;
 
@@ -152,6 +152,10 @@ pub(super) struct PresentMeter {
     /// This device delivers render callbacks at all (API ≥ 33 and the platform accepted the
     /// registration). Until one arrives, `undisplayed` is meaningless and the rail stays down.
     confirms: AtomicBool,
+    /// The learned panel period the cadence statistic quantises against, republished by
+    /// [`Presenter::pump`] (the callback thread has no access to the vsync clock). 0 until the
+    /// grid is known, which simply means cadence is not scored yet.
+    panel_period_ns: AtomicI64,
 }
 
 struct PresentMeterInner {
@@ -166,6 +170,9 @@ struct PresentMeterInner {
     /// Capture→decoded end-to-end µs (skew-corrected, clamped) — always on for the same reason:
     /// the wireless A/B's headline without having to reach the on-screen HUD.
     e2e_us: Vec<u64>,
+    /// The cadence (judder) statistic — the only stat here that is not a latency, and the only
+    /// one that can see a pacing defect. See [`punktfunk_core::phase::PresentIntervals`].
+    intervals: punktfunk_core::phase::PresentIntervals,
 }
 
 impl PresentMeter {
@@ -177,19 +184,33 @@ impl PresentMeter {
                 feed_us: Vec::with_capacity(256),
                 codec_us: Vec::with_capacity(256),
                 e2e_us: Vec::with_capacity(256),
+                intervals: punktfunk_core::phase::PresentIntervals::new(),
             }),
             undisplayed: AtomicI32::new(0),
             confirms: AtomicBool::new(false),
+            panel_period_ns: AtomicI64::new(0),
         }
     }
 
+    /// Republish the learned panel period for the cadence statistic (presenter thread).
+    pub(super) fn set_panel_period(&self, period_ns: i64) {
+        self.panel_period_ns.store(period_ns, Ordering::Relaxed);
+    }
+
     /// One displayed frame's release→displayed latch, µs. Callback thread; poison-proof.
     ///
     /// Also the glass budget's CONFIRM: this frame left the BufferQueue, so one outstanding
     /// release is settled. Clamped at zero — the legacy `arrival` path renders without going
     /// through [`Presenter::pump`], so confirms can outnumber counted releases.
-    pub(super) fn note_latch(&self, latch_us: Option<u64>) {
+    ///
+    /// `present_mono_ns` is SurfaceFlinger's own render timestamp, raw on `CLOCK_MONOTONIC` —
+    /// deliberately not the realtime-rebased instant the latency stats use. Cadence is a
+    /// statistic about *spacing*, and a realtime clock step (NTP) would forge a hitch that never
+    /// happened. Garbage stamps need no special handling here: an implausible one lands in the
+    /// stall or disordered counters rather than the judder ratio.
+    pub(super) fn note_latch(&self, latch_us: Option<u64>, present_mono_ns: i64) {
         self.confirms.store(true, Ordering::Relaxed);
+        let period_ns = self.panel_period_ns.load(Ordering::Relaxed);
         let _ = self
             .undisplayed
             .fetch_update(Ordering::Relaxed, Ordering::Relaxed, |v| {
@@ -200,6 +221,7 @@ impl PresentMeter {
             .lock()
             .unwrap_or_else(std::sync::PoisonError::into_inner);
         g.displays += 1;
+        g.intervals.record(present_mono_ns, period_ns);
         if let Some(l) = latch_us {
             if g.latch_us.len() < 4096 {
                 g.latch_us.push(l);
@@ -258,7 +280,17 @@ impl PresentMeter {
     }
 
     #[allow(clippy::type_complexity)] // one caller unpacks it in place; a struct would be noise
-    fn drain(&self) -> (Vec<u64>, u64, Vec<u64>, Vec<u64>, Vec<u64>) {
+    fn drain(
+        &self,
+    ) -> (
+        Vec<u64>,
+        u64,
+        Vec<u64>,
+        Vec<u64>,
+        Vec<u64>,
+        (u32, u32, u32),
+        Option<punktfunk_core::phase::PresentCadence>,
+    ) {
         let mut g = self
             .inner
             .lock()
@@ -271,6 +303,8 @@ impl PresentMeter {
             std::mem::take(&mut g.feed_us),
             std::mem::take(&mut g.codec_us),
             std::mem::take(&mut g.e2e_us),
+            g.intervals.pending(),
+            g.intervals.take(),
         )
     }
 }
@@ -410,6 +444,11 @@ impl Presenter {
         stats: &crate::stats::VideoStats,
         now_mono_ns: i64,
     ) -> bool {
+        // The callback thread scores cadence but cannot see the vsync clock — republish the grid
+        // it quantises against. Relaxed: a period change is rare and one stale sample is noise.
+        if let Some(c) = clock {
+            meter.set_panel_period(c.panel_period_ns().max(c.period_ns()));
+        }
         // Budget bookkeeping first: reopen on the predicted latch, force-open on the backstop.
         if let Some(f) = &self.inflight {
             if now_mono_ns >= f.reopen_at_ns {
@@ -547,7 +586,11 @@ impl Presenter {
     /// `pace` (decoded→release) / `latch` (release→displayed) /
     /// `feed`+`codec` (the decode stage split: received→queued hand-off/slot wait + the
     /// codec-pure queued→decoded time) / `e2e` (capture→decoded, skew-corrected — the wireless
-    /// A/B headline) / `vsync` (the measured panel period).
+    /// A/B headline) / `vsync` (the measured panel period) /
+    /// `judder` (‰ of present intervals off the modal spacing — the cadence statistic, and the
+    /// only number here that can see a pacing defect) / `mode` (the modal spacing in refreshes:
+    /// 1 at panel rate, 2 for 60-on-120) / `stalls` + `disorder` (excluded from the ratio; see
+    /// [`punktfunk_core::phase::PresentIntervals`]).
     ///
     /// Returns this window's CIRCULAR latch statistics `(vector-mean latch ns mod panel period,
     /// coherence ‰)` when a window actually flushed — the phase-lock reporter's v2 error signal
@@ -561,7 +604,7 @@ impl Presenter {
             return None;
         }
         self.last_flush = Instant::now();
-        let (latch, displays, feed, codec, e2e) = meter.drain();
+        let (latch, displays, feed, codec, e2e, cad_raw, cadence) = meter.drain();
         if self.released == 0 && displays == 0 {
             return None; // idle stream — nothing worth a line
         }
@@ -584,7 +627,8 @@ impl Presenter {
              paceMs p50={:.2} max={:.2} latchMs p50={:.2} max={:.2} \
              feedMs p50={:.2} max={:.2} codecMs p50={:.2} max={:.2} \
              e2eMs p50={:.2} max={:.2} circ={:.2}ms coh={} \
-             vsyncMs={:.2} panelMs={:.2}",
+             vsyncMs={:.2} panelMs={:.2} \
+             judder={}permille mode={}vsync cadN={} stalls={} disorder={} cadPeriodMs={:.2}",
             self.released,
             displays,
             self.paced_drops,
@@ -607,6 +651,12 @@ impl Presenter {
             circ.map(|(_, c)| c).unwrap_or(0),
             period_ms,
             panel_ns as f64 / 1e6,
+            cadence.map(|c| c.judder_permille).unwrap_or(0),
+            cadence.map(|c| c.mode_units).unwrap_or(0),
+            cad_raw.0,
+            cad_raw.1,
+            cad_raw.2,
+            meter.panel_period_ns.load(Ordering::Relaxed) as f64 / 1e6,
         );
         self.released = 0;
         // Margin adaptation, off the MEASURED latch. A release targets the first grid point past

clients/android/native/src/feedback.rs

@@ -18,6 +18,29 @@ use std::time::Duration;
 /// observes its `running=false` flag promptly on teardown.
 const PULL_TIMEOUT: Duration = Duration::from_millis(100);
 
+/// Width of the packed `pad` field in [`pack_rumble`] — 4 bits, i.e. indices 0..15.
+const PAD_BITS: u32 = 4;
+/// The packing is only lossless while every representable pad index fits in [`PAD_BITS`]. This was
+/// a comment before; growing `MAX_PADS` past 16 would have silently aliased pad 16 onto pad 0
+/// rather than failing the build.
+const _: () = assert!(
+    punktfunk_core::input::MAX_PADS <= 1usize << PAD_BITS,
+    "MAX_PADS no longer fits the 4-bit pad field in the packed rumble long"
+);
+
+/// Pack one effective rumble command into the `jlong` `nativeNextRumble` returns.
+///
+/// Layout — mirrored by `unpackRumbleEvent` in `RumbleWire.kt`: bits 49..52 `pad`, 32..47
+/// `backstop_ms`, 16..31 `low`, 0..15 `high`. Always non-negative, so the `-1` timeout/closed
+/// sentinel stays unambiguous. Split out from the JNI entry point purely so it can be tested
+/// without a live session handle — the shift arithmetic is the part worth pinning.
+fn pack_rumble(pad: u16, low: u16, high: u16, backstop_ms: u32) -> jlong {
+    (jlong::from(pad & ((1 << PAD_BITS) - 1)) << 49)
+        | (jlong::from(backstop_ms.min(0xFFFF) as u16) << 32)
+        | (jlong::from(low) << 16)
+        | jlong::from(high)
+}
+
 // HID-output kind tags written into the returned ByteBuffer (Kotlin reads them back).
 const TAG_LED: u8 = 0x01;
 const TAG_PLAYER_LEDS: u8 = 0x02;
@@ -54,12 +77,15 @@ pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeNextRumble(
         // handle.
         let h = unsafe { &*(handle as *const SessionHandle) };
         match h.client.next_rumble_command(PULL_TIMEOUT) {
-            Ok(cmd) => {
-                (jlong::from(cmd.pad & 0xF) << 49)
-                    | (jlong::from(cmd.backstop_ms.min(0xFFFF) as u16) << 32)
-                    | (jlong::from(cmd.low) << 16)
-                    | jlong::from(cmd.high)
-            }
+            // A pad whose coils are ACTIVELY being driven by the 0xD1 haptics stream must not see
+            // wire rumble: `DsDevice` sets `valid_flag0` bit 1 (`HAPTICS_SELECT`) on every rumble
+            // write, and that bit disables the audio-haptics path — so one replayed command would
+            // mute the coils the stream is driving. Gating on *arrival of haptics frames* rather
+            // than on "a stream is open" is what keeps a rumble-only title working: it renders no
+            // haptics audio, so the host emits nothing on 0xD1 and the pad keeps its rumble.
+            // Dropping it here rather than in Kotlin keeps the rule next to the reason.
+            Ok(cmd) if crate::pad_audio::haptics_owns_coils((cmd.pad & 0xF) as u8) => -1,
+            Ok(cmd) => pack_rumble(cmd.pad, cmd.low, cmd.high, cmd.backstop_ms),
             Err(_) => -1, // NoFrame (timeout) or Closed — Kotlin loops on its running flag
         }
     })
@@ -156,7 +182,74 @@ pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeNextHidout(
                 out[3..n].copy_from_slice(&data);
                 n
             }
+            HidOutput::AudioCtl { .. } => {
+                // DS5 pad-audio routing/volumes — no Android replay path yet (the 0xD1 sample
+                // plane isn't rendered here either); drop it like TrackpadHaptic.
+                return -1;
+            }
         };
         n as jint
     })
 }
+
+#[cfg(test)]
+mod pack_rumble_tests {
+    use super::*;
+    use punktfunk_core::input::MAX_PADS;
+
+    /// Kotlin's `unpackRumbleEvent`, transcribed — if these two ever disagree the boundary is
+    /// broken, and nothing else in the build would say so.
+    fn unpack(ev: jlong) -> (u16, u16, u16, u32) {
+        let pad = ((ev >> 49) & 0xF) as u16;
+        let backstop = ((ev >> 32) & 0xFFFF) as u32;
+        let low = ((ev >> 16) & 0xFFFF) as u16;
+        let high = (ev & 0xFFFF) as u16;
+        (pad, low, high, backstop)
+    }
+
+    #[test]
+    fn round_trips_every_field_at_its_extremes() {
+        for &(pad, low, high, backstop) in &[
+            (0u16, 0u16, 0u16, 0u32),
+            (15, 0xFFFF, 0xFFFF, 0xFFFF),
+            (1, 0x1234, 0x5678, 500),
+            (7, 0, 0xFFFF, 2000),
+        ] {
+            let ev = pack_rumble(pad, low, high, backstop);
+            assert_eq!(unpack(ev), (pad, low, high, backstop), "pad {pad}");
+        }
+    }
+
+    #[test]
+    fn every_representable_pad_survives_the_four_bit_field() {
+        for pad in 0..MAX_PADS as u16 {
+            let (got, ..) = unpack(pack_rumble(pad, 1, 2, 3));
+            assert_eq!(got, pad, "pad {pad} aliased in the packed long");
+        }
+    }
+
+    #[test]
+    fn a_packed_command_is_never_negative() {
+        // `-1` is the timeout/closed sentinel; any packed value colliding with it would read as
+        // "no command" and the rumble would simply vanish.
+        assert!(pack_rumble(15, 0xFFFF, 0xFFFF, 0xFFFF) >= 0);
+        assert!(pack_rumble(0, 0, 0, 0) >= 0);
+    }
+
+    #[test]
+    fn an_oversized_backstop_saturates_instead_of_corrupting_the_pad_field() {
+        let ev = pack_rumble(3, 0, 0, u32::MAX);
+        let (pad, _, _, backstop) = unpack(ev);
+        assert_eq!(pad, 3, "a huge backstop must not bleed into the pad bits");
+        assert_eq!(backstop, 0xFFFF);
+    }
+
+    #[test]
+    fn a_stop_is_distinguishable_from_a_hold() {
+        let stop = pack_rumble(2, 0, 0, 0);
+        let hold = pack_rumble(2, 0x8000, 0x8000, 500);
+        assert_ne!(stop, hold);
+        assert_eq!(unpack(stop).1, 0);
+        assert_eq!(unpack(stop).2, 0);
+    }
+}

clients/android/native/src/lib.rs

@@ -37,6 +37,8 @@ mod discovery;
 mod feedback;
 #[cfg(target_os = "android")]
 mod mic;
+/// Tier-A DualSense pad audio: the 0xD1 plane rendered on the pad's own USB endpoint.
+mod pad_audio;
 mod session;
 mod stats;
 // Ungated like `discovery`: pure `jni` + `punktfunk_core::wol` (no Android framework), so it links

clients/android/native/src/session/connect.rs

@@ -145,6 +145,7 @@ pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeConnect<'lo
     timeout_ms: jint,
     launch: JString<'local>,
     device_name: JString<'local>,
+    pad_audio_ok: jboolean,
 ) -> jlong {
     let host: String = match env.get_string(&host) {
         Ok(s) => s.into(),
@@ -268,7 +269,16 @@ pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeConnect<'lo
         // CLIENT_CAP_PHASE_LOCK is honest: the async decode loop's presenter feeds
         // report_phase (advisory in v1 — the host arms on report receipt — but the Hello
         // should say what the client does).
-        punktfunk_core::quic::CLIENT_CAP_PHASE_LOCK,
+        // CLIENT_CAP_PAD_AUDIO is the SESSION-level negotiation, separate from the per-pad
+        // arrival bits: without it the host never sets HOST_CAP_PAD_AUDIO and never emits 0xD1,
+        // so declaring a pad's render caps later would have nothing to gate. Gated on the
+        // settings so a user with pad audio off does not make the host provision endpoints.
+        punktfunk_core::quic::CLIENT_CAP_PHASE_LOCK
+            | if pad_audio_ok != 0 {
+                punktfunk_core::quic::CLIENT_CAP_PAD_AUDIO
+            } else {
+                0
+            },
         // Slice-progressive delivery, by decoder truth (Kotlin probes FEATURE_PartialFrame on
         // every decoder this device would use; `debug.punktfunk.force_parts` overrides for the
         // on-glass experiment): AU prefixes then arrive as `Frame::part` pieces and the decode
@@ -291,6 +301,8 @@ pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeConnect<'lo
                 audio: Mutex::new(None),
                 #[cfg(target_os = "android")]
                 mic: Mutex::new(None),
+                #[cfg(target_os = "android")]
+                pad_audio: Mutex::new(None),
                 // A fresh session is never muted (mute is per-session UI state, not a setting).
                 mic_muted: Arc::new(std::sync::atomic::AtomicBool::new(false)),
             };

clients/android/native/src/session/mod.rs

@@ -61,6 +61,11 @@ pub(crate) struct SessionHandle {
     audio: Mutex<Option<crate::audio::AudioPlayback>>,
     #[cfg(target_os = "android")]
     mic: Mutex<Option<crate::mic::MicCapture>>,
+    /// Tier-A DualSense pad audio (the 0xD1 plane), started by `nativeStartPadAudio` once Kotlin
+    /// has claimed the pad's audio interface and handed its descriptor over. Session-lifetime and
+    /// `Option` because a session may have no wired DualSense at all, which is the common case.
+    #[cfg(target_os = "android")]
+    pub(crate) pad_audio: Mutex<Option<crate::pad_audio::PadAudio>>,
     /// In-stream mic mute, set via `nativeSetMicMuted` and read per 10 ms frame by the mic's
     /// encode loop ([`crate::mic`]). Session-lifetime rather than per-[`crate::mic::MicCapture`]
     /// for the same reason the stats gate is: the mic stops and restarts across a surface
@@ -99,6 +104,14 @@ impl SessionHandle {
     fn stop_mic(&self) {
         let _ = self.mic.lock().unwrap().take();
     }
+
+    /// Stop pad audio. Dropping the [`crate::pad_audio::PadAudio`] joins its render thread, which
+    /// is what guarantees nothing is still writing to the descriptor when Kotlin closes the
+    /// `UsbDeviceConnection`. Idempotent.
+    #[cfg(target_os = "android")]
+    pub(crate) fn stop_pad_audio(&self) {
+        let _ = self.pad_audio.lock().unwrap().take();
+    }
 }
 
 impl Drop for SessionHandle {
@@ -108,6 +121,8 @@ impl Drop for SessionHandle {
         self.stop_audio();
         #[cfg(target_os = "android")]
         self.stop_mic();
+        #[cfg(target_os = "android")]
+        self.stop_pad_audio();
     }
 }
 

clients/android/native/src/session/planes.rs

@@ -460,6 +460,111 @@ pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeStopMic(
     })
 }
 
+/// `NativeBridge.nativeStartPadAudio(handle, pad, fd, haptics, speaker): Boolean` — start tier-A
+/// DualSense pad audio on a descriptor Kotlin has already obtained.
+///
+/// `fd` comes from `UsbDeviceConnection.getFileDescriptor()` **after** claiming the pad's audio
+/// streaming interface. Kotlin owns that connection and **must keep it open until
+/// `nativeStopPadAudio` returns**: the renderer borrows the descriptor and never closes it, so
+/// closing early would pull it out from under an in-flight isochronous transfer.
+///
+/// Returns `false` when there is nothing to render (both kinds disabled) or the thread would not
+/// start. A kernel that refuses the interface claim is NOT reported here — the renderer discovers
+/// that on its own thread and degrades to tier C, because some OEM kernels refuse and there is no
+/// app-side fix worth blocking a session on.
+#[no_mangle]
+#[cfg(target_os = "android")]
+pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeStartPadAudio(
+    _env: JNIEnv,
+    _this: JObject,
+    handle: jlong,
+    pad: jni::sys::jint,
+    fd: jni::sys::jint,
+    haptics: jboolean,
+    speaker: jboolean,
+) -> jboolean {
+    jni_guard(0, || {
+        if handle == 0 || fd < 0 || !(0..16).contains(&pad) {
+            return 0;
+        }
+        // SAFETY: live handle per the nativeConnect/nativeClose contract.
+        let h = unsafe { &*(handle as *const SessionHandle) };
+        // Replace any previous renderer first: dropping it joins the old thread, so two of them
+        // can never hold the same descriptor at once.
+        h.stop_pad_audio();
+        // The capability declaration and the rumble suppression are NOT done here: the renderer
+        // makes both only once its USB stream actually opens (see `pad_audio::render`). Doing them
+        // at spawn time would, on a kernel that refuses the interface claim, take the pad off wire
+        // rumble and give it nothing in return — no haptics of any kind.
+        match crate::pad_audio::start(
+            std::sync::Arc::clone(&h.client),
+            pad as u8,
+            fd,
+            haptics != 0,
+            speaker != 0,
+        ) {
+            Some(p) => {
+                *h.pad_audio.lock().unwrap() = Some(p);
+                1
+            }
+            None => 0,
+        }
+    })
+}
+
+/// `NativeBridge.nativePadAudioSelfTest(fd, seconds, hz): Int` — drive the pad directly with a
+/// tone through the real client render path, with no host and no session involved.
+///
+/// The check a standalone harness cannot make: it owns its descriptor by construction, so it can
+/// never reveal that the client handed the renderer a descriptor something else was already
+/// driving. Returns sample frames written, or negative on failure (see `pad_audio::SelfTest`).
+#[no_mangle]
+#[cfg(target_os = "android")]
+pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativePadAudioSelfTest(
+    _env: JNIEnv,
+    _this: JObject,
+    fd: jni::sys::jint,
+    seconds: jni::sys::jint,
+    hz: jni::sys::jint,
+) -> jni::sys::jint {
+    jni_guard(-1, || {
+        if fd < 0 {
+            return -1;
+        }
+        // SAFETY: Kotlin holds the owning UsbDeviceConnection open across this call and drives no
+        // other transfers on it (it opens a dedicated connection for exactly this).
+        unsafe { crate::pad_audio::self_test(fd, seconds, hz) }
+    })
+}
+
+/// `NativeBridge.nativeStopPadAudio(handle, pad)` — stop tier-A pad audio and join its thread.
+///
+/// Returns only once the render thread is joined, which is the point: Kotlin may close the
+/// `UsbDeviceConnection` as soon as this returns and not before.
+#[no_mangle]
+#[cfg(target_os = "android")]
+pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeStopPadAudio(
+    _env: JNIEnv,
+    _this: JObject,
+    handle: jlong,
+    pad: jni::sys::jint,
+) {
+    jni_guard((), || {
+        if handle != 0 {
+            // SAFETY: live handle per the nativeConnect/nativeClose contract.
+            let h = unsafe { &*(handle as *const SessionHandle) };
+            h.stop_pad_audio();
+            if (0..16).contains(&pad) {
+                // Withdraw the capability and hand the pad back to wire rumble, in that order:
+                // the host stops sending 0xD1 before tier C resumes, so the two never overlap.
+                h.client.set_pad_audio_caps(pad as u8, 0);
+                crate::pad_audio::set_tier_a(pad as u8, false);
+                crate::pad_audio::clear_haptics_liveness(pad as u8);
+            }
+        }
+    })
+}
+
 /// `NativeBridge.nativeSetMicMuted(handle, muted)` — mute/unmute the mic uplink mid-stream.
 ///
 /// Muting deliberately does NOT stop the capture: the AAudio input stream, the input-preset rung

clients/apple/Sources/PunktfunkKit/Gamepad/ControllerTester.swift

@@ -12,7 +12,7 @@ import GameController
 public final class ControllerTester: ObservableObject {
     // `.manual`: the panel's toggles hold a level until changed — no session wire refreshes
     // exist here to keep the renderer's staleness watchdog fed.
-    private let renderer = RumbleRenderer(policy: .manual)
+    private let renderer = RumbleRenderer()
     private weak var controller: GCController?
 
     /// The rumble backend now in use — "DualSense HID · USB/Bluetooth", "CoreHaptics", or "—" —

clients/apple/Sources/PunktfunkKit/Gamepad/DualSenseHID.swift

@@ -21,8 +21,12 @@ import os
 
 private let log = Logger(subsystem: "io.unom.punktfunk", category: "gamepad")
 
-/// Opens the first connected Sony DualSense and forwards motor rumble to it over raw HID.
-/// Single-pad model (we forward exactly one controller), so the first match is the right one.
+/// Opens one connected Sony DualSense and forwards motor rumble to it over raw HID.
+///
+/// A caller that owns a particular pad passes the location id it wants (see
+/// `open(preferringLocationID:)`); the renderer takes that from the `GCController` it is bound to,
+/// so with two DualSenses attached each renderer drives its own device. Without a preference the
+/// lowest location id wins — an arbitrary but *stable* choice, where `Set.first` was neither.
 final class DualSenseHID {
     private let manager: IOHIDManager
     private var device: IOHIDDevice?
@@ -43,9 +47,57 @@ final class DualSenseHID {
 
     deinit { close() }
 
-    /// Find and open the first connected DualSense. Returns false if none is present or it can't
-    /// be opened (caller then falls back to CoreHaptics).
-    func open() -> Bool {
+    /// The IOKit location id of the device this instance opened — the handle a caller correlates
+    /// with its `GCController`. `nil` until a successful `open`.
+    private(set) var locationID: UInt32?
+
+    /// A device's location id, or `nil` if IOKit does not report one.
+    static func locationID(of dev: IOHIDDevice) -> UInt32? {
+        IOHIDDeviceGetProperty(dev, kIOHIDLocationIDKey as CFString) as? UInt32
+    }
+
+    /// Every connected DualSense/Edge, by location id — what a caller pairs against its controllers.
+    static func attachedLocationIDs() -> [UInt32] {
+        let mgr = IOHIDManagerCreate(kCFAllocatorDefault, IOOptionBits(kIOHIDOptionsTypeNone))
+        let matches = productIDs.map { pid in
+            [kIOHIDVendorIDKey: vendorSony, kIOHIDProductIDKey: pid] as CFDictionary
+        }
+        IOHIDManagerSetDeviceMatchingMultiple(mgr, matches as CFArray)
+        guard IOHIDManagerOpen(mgr, IOOptionBits(kIOHIDOptionsTypeNone)) == kIOReturnSuccess else {
+            return []
+        }
+        defer { IOHIDManagerClose(mgr, IOOptionBits(kIOHIDOptionsTypeNone)) }
+        let devices = IOHIDManagerCopyDevices(mgr) as? Set<IOHIDDevice> ?? []
+        return devices.compactMap(locationID(of:)).sorted()
+    }
+
+    /// Which attached device to drive, as an index into `ids` — the whole selection rule, pure so
+    /// it can be tested without an `IOHIDDevice` (which cannot be constructed).
+    ///
+    /// `IOHIDManagerCopyDevices` returns an unordered `Set`, so the previous `Set.first` was not
+    /// merely arbitrary — it can differ between two calls in one process. With two DualSenses that
+    /// made each renderer's pad→device binding a coin flip: both could land on the same device
+    /// (one pad's rumble coming out of the other, and the two per-instance write dedupes fighting
+    /// over it) or split by luck. An explicit location id makes the binding deterministic; the
+    /// lowest-id fallback at least makes it stable. `nil` ids sort last so a device IOKit cannot
+    /// place never displaces one it can.
+    static func preferredIndex(among ids: [UInt32?], preferring wanted: UInt32?) -> Int? {
+        if let wanted, let hit = ids.firstIndex(where: { $0 == wanted }) { return hit }
+        return ids.indices.min { (ids[$0] ?? .max) < (ids[$1] ?? .max) }
+    }
+
+    /// Pick the device to drive from everything attached (see [`preferredIndex`]).
+    static func pick(_ devices: Set<IOHIDDevice>, preferring wanted: UInt32?) -> IOHIDDevice? {
+        let ordered = Array(devices)
+        guard let i = preferredIndex(among: ordered.map(locationID(of:)), preferring: wanted) else {
+            return nil
+        }
+        return ordered[i]
+    }
+
+    /// Find and open a connected DualSense, preferring the one at `preferredLocationID`. Returns
+    /// false if none is present or it can't be opened (caller then falls back to CoreHaptics).
+    func open(preferringLocationID preferred: UInt32? = nil) -> Bool {
         let matches = Self.productIDs.map { pid in
             [kIOHIDVendorIDKey: Self.vendorSony, kIOHIDProductIDKey: pid] as CFDictionary
         }
@@ -55,13 +107,21 @@ final class DualSenseHID {
             return false
         }
         guard let devices = IOHIDManagerCopyDevices(manager) as? Set<IOHIDDevice>,
-              let dev = devices.first
+              let dev = Self.pick(devices, preferring: preferred)
         else {
             log.info("rumble: no DualSense HID device found — falling back to CoreHaptics")
             IOHIDManagerClose(manager, IOOptionBits(kIOHIDOptionsTypeNone))
             return false
         }
         device = dev
+        locationID = Self.locationID(of: dev)
+        if let preferred, locationID != preferred {
+            // Not fatal — one pad still gets rumble — but with two pads attached it means this
+            // renderer is driving the wrong one, and it is invisible without the log line.
+            log.error(
+                "rumble: wanted DualSense at location \(preferred, privacy: .public) but opened \(self.locationID.map(String.init) ?? "unknown", privacy: .public)"
+            )
+        }
         let transport = IOHIDDeviceGetProperty(dev, kIOHIDTransportKey as CFString) as? String
         bluetooth = transport?.lowercased().contains("bluetooth") ?? false
         log.info("rumble: DualSense raw-HID rumble active (transport=\(self.transport, privacy: .public))")
@@ -70,8 +130,16 @@ final class DualSenseHID {
 
     /// Drive the motors. `low` = left/heavy (low-frequency), `high` = right/light (high-frequency),
     /// each 0...255. (0, 0) stops.
-    func rumble(low: UInt8, high: UInt8) {
-        guard let dev = device else { return }
+    ///
+    /// Returns whether the write reached the device. The caller needs this: it used to be logged
+    /// and swallowed, so a failed write still counted as a successful render. That matters most
+    /// for a **stop**, which has nothing behind it — the renderer stamps its write clock even on
+    /// failure, the keepalive re-write only fires for non-zero levels, and the ticker is cancelled
+    /// once the target is `(0, 0)`. On USB there is no firmware timeout either, so a swallowed
+    /// stop left the motors running with nothing scheduled to try again.
+    @discardableResult
+    func rumble(low: UInt8, high: UInt8) -> Bool {
+        guard let dev = device else { return false }
         let report = bluetooth
             ? Self.bluetoothReport(low: low, high: high)
             : Self.usbReport(low: low, high: high)
@@ -81,7 +149,9 @@ final class DualSenseHID {
         }
         if rc != kIOReturnSuccess {
             log.error("rumble: IOHIDDeviceSetReport failed (0x\(String(format: "%08x", rc), privacy: .public))")
+            return false
         }
+        return true
     }
 
     func close() {

clients/apple/Sources/PunktfunkKit/Gamepad/GamepadFeedback.swift

@@ -65,7 +65,7 @@ public final class GamepadFeedback {
         #if os(iOS)
         if UserDefaults.standard.bool(forKey: DefaultsKey.rumbleOnDevice),
             CHHapticEngine.capabilitiesForHardware().supportsHaptics {
-            deviceRumble = RumbleRenderer(policy: .session, actuator: .device)
+            deviceRumble = RumbleRenderer(actuator: .device)
         } else {
             deviceRumble = nil
         }
@@ -117,7 +117,15 @@ public final class GamepadFeedback {
             reset(slot.controller)
             slots[pad] = nil
             let renderer = withRouting { rumbleByPad.removeValue(forKey: pad) }
-            renderer?.stop()
+            // OFF the main actor. `RumbleRenderer.stop()` is a `queue.sync`, and its body is a
+            // per-motor `CHHapticEngine.stop()` — an XPC round trip to gamecontrollerd, which the
+            // renderer's own notes record as able to hang — plus `DualSenseHID.close()`, whose
+            // blocking `IOHIDDeviceSetReport` goes to a device that has just departed. It also
+            // queues behind any in-flight `setup()`. This runs on every unplug and every pin
+            // change, and the main thread is what drives the presenter's CADisplayLink, so
+            // blocking here hitches the picture mid-stream. The renderer is already detached from
+            // routing above, so nothing observes it after this point.
+            if let renderer { Task.detached { renderer.stop() } }
         }
         for (pad, controller) in want {
             if let slot = slots[pad] {
@@ -128,7 +136,7 @@ public final class GamepadFeedback {
                 replay(slot)
             } else {
                 slots[pad] = Slot(controller: controller)
-                let renderer = RumbleRenderer(policy: .session)
+                let renderer = RumbleRenderer()
                 renderer.retarget(controller)
                 withRouting { rumbleByPad[pad] = renderer }
             }
@@ -282,6 +290,12 @@ public final class GamepadFeedback {
     private func reset(_ controller: GCController?) {
         guard let c = controller else { return }
         c.playerIndex = .indexUnset
+        // Put the lightbar out too. This class is what turned it on (see the `Led` and
+        // `PlayerLeds` arms), and every DS write is valid-flag-selective, so a colour the game
+        // set stays lit in firmware after the stream ends — back at the launcher, or for a pad
+        // that merely left the forwarded set. A DS4 is cleared incidentally because its player
+        // indicator IS the lightbar; a DualSense is not.
+        c.light?.color = GCColor(red: 0, green: 0, blue: 0)
         if let ds = c.extendedGamepad as? GCDualSenseGamepad {
             ds.leftTrigger.setModeOff()
             ds.rightTrigger.setModeOff()

clients/apple/Sources/PunktfunkKit/Gamepad/RumbleRenderer.swift

@@ -43,8 +43,14 @@ enum RumbleTuning {
 
     /// Wire amplitude (0...0xFFFF) → CoreHaptics intensity (0...1).
     static func amplitude(_ wire: UInt16) -> Float { Float(wire) / 65535 }
-    /// Wire amplitude → DualSense HID motor byte.
-    static func hidByte(_ wire: UInt16) -> UInt8 { UInt8(wire >> 8) }
+    /// Wire amplitude → DualSense HID motor byte. A nonzero command never collapses to silence:
+    /// the top byte of anything below 0x0100 is 0, so a weak-but-real rumble used to render as
+    /// nothing at all on this path. Floored at 1 — imperceptibly light, but moving. (Android's
+    /// `toAmplitude` has always done this; this was the odd one out.)
+    static func hidByte(_ wire: UInt16) -> UInt8 {
+        let b = UInt8(wire >> 8)
+        return wire != 0 && b == 0 ? 1 : b
+    }
     /// Single-actuator pads render whichever motor is stronger.
     static func combined(low: UInt16, high: UInt16) -> UInt16 { max(low, high) }
     /// Are two baked levels the same (skip the rebuild)?
@@ -81,10 +87,11 @@ enum RumbleTuning {
 ///  4. **Escalating stop.** A throwing `player.stop` means the engine's state is unknown — the
 ///     whole engine is stopped (silencing every player it hosts) and lazily rebuilt behind the
 ///     exponential backoff.
-///  5. **Staleness watchdog** (`Policy.session`): audible with no wire command for
-///     `sessionStaleSeconds` → force silence. A lost stop can outlive the host's 500 ms heal
-///     only if the channel itself died, and then the pad must not buzz forever. `Policy.manual`
-///     (the settings test panel) instead holds a level until it is changed.
+///  5. **No staleness watchdog here.** There was one, keyed off a `Policy` type and a
+///     `sessionStaleSeconds`; both are gone. Every liveness decision — lease expiry, legacy-host
+///     staleness, session close — now belongs to punktfunk-core's shared policy engine
+///     (`client/rumble.rs`), which emits explicit zero commands, so this renderer applies what it
+///     is told and never decides on its own when a level should end.
 ///
 /// Engines are created lazily on the first nonzero amplitude and torn down on retarget;
 /// failures (pads without haptics, engine resets) downgrade to silence — rumble is best-effort
@@ -93,17 +100,6 @@ enum RumbleTuning {
 /// `@unchecked Sendable` is sound because every property is read and written only inside
 /// `queue` closures — the serial queue is the synchronization.
 final class RumbleRenderer: @unchecked Sendable {
-    /// Who ends an un-refreshed nonzero target. Session mode applies the core policy engine's
-    /// commands verbatim — the engine (punktfunk-core `client/rumble.rs`) owns every lease,
-    /// staleness, and close decision and emits explicit zeros, so the renderer keeps NO
-    /// staleness policy of its own anymore. The controller test panel (`manual`) holds a slider
-    /// level indefinitely; both are identical renderer-side today, the distinction is kept for
-    /// the call sites' intent.
-    struct Policy {
-        static let session = Policy()
-        static let manual = Policy()
-    }
-
     /// Which physical actuator this renderer drives: the forwarded controller's haptics engine
     /// (the default), or THIS device's own Taptic Engine (`CHHapticEngine()`) — the opt-in
     /// "rumble on this device" mirror for phone-clip pads that ship without rumble motors.
@@ -115,7 +111,6 @@ final class RumbleRenderer: @unchecked Sendable {
     }
 
     private let queue = DispatchQueue(label: "io.unom.punktfunk.haptics", qos: .userInteractive)
-    private let policy: Policy
     private let actuator: Actuator
 
     /// One finite haptic play on a motor: the player plus when (engine timeline) it expires.
@@ -190,8 +185,7 @@ final class RumbleRenderer: @unchecked Sendable {
         ((0, 0), DispatchTime(uptimeNanoseconds: 0))
     #endif
 
-    init(policy: Policy = .session, actuator: Actuator = .controller) {
-        self.policy = policy
+    init(actuator: Actuator = .controller) {
         self.actuator = actuator
     }
 
@@ -459,6 +453,18 @@ final class RumbleRenderer: @unchecked Sendable {
         if split {
             low = makeMotor(haptics, .leftHandle, sharpness: RumbleTuning.sharpnessLow)
             high = makeMotor(haptics, .rightHandle, sharpness: RumbleTuning.sharpnessHigh)
+            // HALF a split is worse than none, and it used to pass silently: only the all-nil case
+            // below counts as failure, so one surviving handle left `ok` true and `reportHealth(nil)`
+            // announced HEALTHY. What actually rendered was wrong in a direction that depends on
+            // which handle died — lose `high` and `render` falls to the combined branch (selected
+            // purely by `high != nil`), playing max(low, high) on the LEFT handle at the combined
+            // sharpness; lose `low` and the split branch's reconcile no-ops on the nil slot, so the
+            // heavy motor is discarded outright. Tear the survivor down and take the combined path,
+            // which at least renders both motors somewhere.
+            if low == nil || high == nil {
+                log.warning("rumble: only one split-handle engine came up — falling back to combined")
+                teardown() // disarms handlers, stops the survivor's players + engine, nils both
+            }
         } else {
             low = makeMotor(haptics, .default, sharpness: RumbleTuning.sharpnessCombined)
         }
@@ -587,7 +593,9 @@ final class RumbleRenderer: @unchecked Sendable {
         #if os(macOS)
         guard let c, c.extendedGamepad is GCDualSenseGamepad else { return false }
         let hid = DualSenseHID()
-        guard hid.open() else { return false }
+        // Ask for the device this renderer's controller actually is, so two attached DualSenses
+        // do not both get driven through whichever one an unordered Set happened to yield first.
+        guard hid.open(preferringLocationID: Self.hidLocationID(for: c)) else { return false }
         dualSenseHID = hid
         return true
         #else
@@ -595,6 +603,24 @@ final class RumbleRenderer: @unchecked Sendable {
         #endif
     }
 
+    #if os(macOS)
+    /// Correlate a `GCController` with an IOKit location id.
+    ///
+    /// GameController exposes no location id, so there is no direct mapping. What it does expose is
+    /// a stable per-controller ordering, and IOKit's location ids are stable per port: pairing the
+    /// two by rank makes each renderer pick a *distinct* device, which is the property that was
+    /// missing. With one pad attached this is the same device it always was.
+    static func hidLocationID(for c: GCController) -> UInt32? {
+        let ids = DualSenseHID.attachedLocationIDs()
+        guard ids.count > 1 else { return ids.first }
+        let peers = GCController.controllers().filter { $0.extendedGamepad is GCDualSenseGamepad }
+        guard let rank = peers.firstIndex(where: { $0 === c }), rank < ids.count else {
+            return ids.first
+        }
+        return ids[rank]
+    }
+    #endif
+
     /// Write the target to the DualSense over HID if that's the active backend; false → not a
     /// HID pad, so the caller renders via CoreHaptics. Deduped on the pad's 0...255 resolution,
     /// with a periodic keepalive re-write while nonzero (the ticker calls back in here).
@@ -605,8 +631,20 @@ final class RumbleRenderer: @unchecked Sendable {
         let keepalive = levels != (0, 0)
             && seconds(since: lastHidWrite.at) > RumbleTuning.hidKeepaliveSeconds
         if levels != lastHidWrite.levels || keepalive {
-            hid.rumble(low: levels.0, high: levels.1)
-            lastHidWrite = (levels, .now())
+            if hid.rumble(low: levels.0, high: levels.1) {
+                lastHidWrite = (levels, .now())
+            } else {
+                // The write did not reach the device. Do NOT stamp the clock — that would claim a
+                // render that never happened, and for a stop there is nothing behind it: the
+                // keepalive only re-writes non-zero levels and the ticker is cancelled once the
+                // target is (0, 0), so the motors would keep running with nothing scheduled.
+                // Drop the handle instead: the pad reverts to CoreHaptics, and a reconnect
+                // rebuilds it. Health is reported so the state is visible rather than silent.
+                log.error("rumble: HID write failed — dropping the handle, falling back")
+                closeHID()
+                reportHealth("Lost the direct connection to this DualSense; using the system path.")
+                return false
+            }
         }
         return true
         #else

clients/apple/Sources/PunktfunkKit/Video/Stage2Pipeline.swift

@@ -474,6 +474,7 @@ private final class DeadlineLinkDelegate: NSObject, CAMetalDisplayLinkDelegate {
         // The link's own pipeline depth, measured: how far ahead of glass this vend runs.
         let leadS = update.targetPresentationTimestamp - CACurrentMediaTime()
         stats?.vendLead(ms: leadS * 1000)
+        stats?.notePanelTarget(mediaTime: update.targetPresentationTimestamp)
         // Same measurement into the floor meter (as a LatencyMeter sample: end = now, start =
         // now − lead) — its 1 s p50 is the OS present floor SessionModel shaves off.
         if leadS > 0, let floorMeter {
@@ -562,6 +563,112 @@ final class PresentGate: @unchecked Sendable {
     }
 }
 
+/// One window's present-cadence summary (see `PresentIntervals`).
+struct PresentCadence: Equatable {
+    /// The most common spacing, in whole panel refreshes: 1 at panel rate, 2 for 60-on-120.
+    let modeUnits: Int
+    /// Fraction of intervals that were NOT the mode, in ‰. **The judder number.**
+    let judderPermille: Int
+    let samples: Int
+    /// Spacings wider than `maxUnits` — stalls, not judder.
+    let stalls: Int
+    /// Present instants that did not advance (duplicate/out-of-order callbacks).
+    let disordered: Int
+}
+
+/// Present-interval distribution in whole panel refreshes — the cadence (judder) statistic.
+///
+/// A **verbatim port of `punktfunk_core::phase::PresentIntervals`**, in the same spirit as
+/// `PhaseReporter.circularLatch` above: the three clients must publish the SAME statistic, so the
+/// numbers can be compared across platforms and so a feature-on/off A/B uses one ruler. Any change
+/// here belongs in the Rust original first — including the tie-break, which is spelled out on both
+/// sides precisely because the two languages' `max` disagree about which equal element wins.
+///
+/// Every other stat we publish is a latency: a difference between two points on one frame. No
+/// latency can see judder, because judder is a property of the *sequence*. A stream that shows each
+/// frame one refresh early and the next one late has excellent percentiles and looks broken.
+///
+/// Fed the MEASURED on-glass instant, never the requested present time — the latter would measure
+/// our own intent and report a perfect cadence no matter what the display did.
+struct PresentIntervals {
+    /// Largest spacing still treated as cadence; wider is a stall, counted apart.
+    private static let maxUnits = 8
+    /// Minimum intervals before a summary means anything (matches `circularLatch`'s bar).
+    private static let minSamples = 8
+    /// A backwards step larger than this is a bogus timestamp, not a reordered delivery, so the
+    /// run re-anchors rather than holding the old instant. Without it, one garbage far-future
+    /// stamp latches the statistic and every later present scores as disordered for the whole
+    /// session — observed on glass on Android, 2026-08-05.
+    private static let reanchorNs: Int64 = 100_000_000
+
+    private var lastPresentNs: Int64 = 0
+    private var hist = [Int](repeating: 0, count: PresentIntervals.maxUnits + 1)
+    private var samples = 0
+    private var stalls = 0
+    private var disordered = 0
+
+    /// Forget the previous instant without discarding the window's counts — a discontinuity where
+    /// the next present does not continue this cadence.
+    mutating func split() { lastPresentNs = 0 }
+
+    /// Fold one on-glass instant. A non-positive `periodNs` means the grid is not known yet and
+    /// the sample is held as the new predecessor without being scored.
+    mutating func record(presentNs: Int64, periodNs: Int64) {
+        let prev = lastPresentNs
+        lastPresentNs = presentNs
+        guard prev > 0, periodNs > 0 else { return }
+        let spacing = presentNs - prev
+        if spacing <= 0 {
+            // Hold the LATER instant so one reordered delivery cannot corrupt every following
+            // spacing — but only when the step back is small enough to BE a reordering. Beyond
+            // that the old instant is the bogus one (see `reanchorNs`) and the run re-anchors
+            // onto the new sample, which `lastPresentNs` already holds.
+            disordered += 1
+            if prev - presentNs < PresentIntervals.reanchorNs {
+                lastPresentNs = prev
+            }
+            return
+        }
+        // Nearest whole refresh: a present is "on the grid" if it is closer to this vblank than
+        // the next, which is exactly what the display did with it.
+        let units = Int((spacing * 2 + periodNs) / (periodNs * 2))
+        if units > PresentIntervals.maxUnits {
+            stalls += 1
+            return
+        }
+        hist[units] += 1
+        samples += 1
+    }
+
+    /// This window's summary, or nil under `minSamples`.
+    func summary() -> PresentCadence? {
+        guard samples >= PresentIntervals.minSamples else { return nil }
+        // Ties resolve to the SMALLEST spacing — see the Rust original: `max_by_key` takes the
+        // last maximum and Swift's `max(by:)` the first, so this is written out on both sides.
+        var modeUnits = 0
+        var modeCount = 0
+        for (i, c) in hist.enumerated() where c > modeCount {
+            modeCount = c
+            modeUnits = i
+        }
+        return PresentCadence(
+            modeUnits: modeUnits,
+            judderPermille: (samples - modeCount) * 1000 / samples,
+            samples: samples, stalls: stalls, disordered: disordered)
+    }
+
+    /// Drain the window. The previous instant SURVIVES — the cadence continues across a window
+    /// boundary, and dropping it would manufacture one unscored interval per window.
+    mutating func take() -> PresentCadence? {
+        let out = summary()
+        hist = [Int](repeating: 0, count: PresentIntervals.maxUnits + 1)
+        samples = 0
+        stalls = 0
+        disordered = 0
+        return out
+    }
+}
+
 /// PUNKTFUNK_PRESENT_DEBUG=1 aggregation: one printed line per second from the render thread with
 /// the decode rate, render outcomes, the slowest render call (≈ nextDrawable wait) and the deltas
 /// between system-reported on-glass times (vsync-aligned presents show clean refresh-period
@@ -588,6 +695,50 @@ private final class PresentDebugStats: @unchecked Sendable {
     /// 120 Hz panel saturates this at ~maximumDrawableCount; stage-3 pegs it at the gate depth).
     private var inFlight = 0
     private var maxInFlight = 0
+    /// The cadence (judder) statistic — the only number here that is not a latency, and the only
+    /// one that can see a pacing defect. `glassDeltasMs` above is the same raw material reported
+    /// as a percentile, which cannot distinguish a steady 2-refresh cadence from an alternating
+    /// 1-and-3 one: same mean, same median, one of them visibly broken.
+    private var intervals = PresentIntervals()
+    /// The panel period cadence quantises against: seeded from the display mode and refined from
+    /// the link's own reported period, mirroring `punktfunk_core::phase::PanelGrid`'s seed-then-
+    /// correct design. 0 until known, which simply means cadence is not scored yet.
+    private var panelPeriodNs: Int64 = 0
+    /// Deadline-pacing period learner state (see `notePanelTarget`). Re-armed each window so a
+    /// mode or VRR rate change is tracked both ways rather than latching the first value seen.
+    private var lastTargetS: CFTimeInterval = 0
+    private var minTargetSpacingS: CFTimeInterval = 0
+    /// Whether the verbose per-second line prints. The cadence line always does: a smoothness
+    /// defect must not be invisible until someone thinks to set an env var.
+    private let verbose: Bool
+
+    init(verbose: Bool) { self.verbose = verbose }
+
+    /// Seed or refine the panel period (render/link thread).
+    func setPanelPeriod(ns: Int64) {
+        guard ns > 0 else { return }
+        lock.lock()
+        panelPeriodNs = ns
+        lock.unlock()
+    }
+
+    /// Deadline pacing has no reported period, so learn it from the link's own target instants.
+    /// Those tick at the panel rate whether or not WE present, which is what makes the window
+    /// minimum the true period — the same reasoning (and the same guard band) `PhaseReporter`
+    /// uses above. Learning it from on-glass spacings instead would read a 60-on-120 stream as a
+    /// 60 Hz panel and mislabel the cadence mode.
+    func notePanelTarget(mediaTime t: CFTimeInterval) {
+        lock.lock()
+        defer { lock.unlock() }
+        defer { lastTargetS = t }
+        guard lastTargetS > 0 else { return }
+        let d = t - lastTargetS
+        guard d > 0.0005, d < 0.1 else { return }
+        if minTargetSpacingS == 0 || d < minTargetSpacingS {
+            minTargetSpacingS = d
+            panelPeriodNs = Int64(d * 1_000_000_000)
+        }
+    }
 
     func emptyWake() { lock.lock(); empty += 1; lock.unlock() }
 
@@ -624,8 +775,13 @@ private final class PresentDebugStats: @unchecked Sendable {
             if lastGlassNs > 0 { glassDeltasMs.append(Double(atNs - lastGlassNs) / 1e6) }
             lastGlassNs = atNs
             latchMs.append(Double(atNs - issuedNs) / 1e6)
+            intervals.record(presentNs: atNs, periodNs: panelPeriodNs)
         } else {
+            // A dropped drawable never reached glass, so it is not a cadence event — but the
+            // NEXT one does not continue the previous interval either. Split rather than let
+            // the gap read as judder.
             dropped += 1
+            intervals.split()
         }
         lock.unlock()
     }
@@ -656,6 +812,9 @@ private final class PresentDebugStats: @unchecked Sendable {
             smoothing.overflowDrops, smoothing.underflows, maxRenderMs, inflightMax,
             gate?.drainForced() ?? 0, p50, dMax, deltas.count, latchP50, latchMax,
             vendP50, vendMax)
+        let cadence = intervals.take()
+        let verbose = self.verbose
+        minTargetSpacingS = 0 // re-arm the period learner for the next window
         ok = 0; failed = 0; empty = 0; dropped = 0; gated = 0; noDrawable = 0
         maxRenderMs = 0
         maxInFlight = inFlight // the window peak restarts from the live depth
@@ -663,6 +822,21 @@ private final class PresentDebugStats: @unchecked Sendable {
         latchMs.removeAll(keepingCapacity: true)
         vendLeadMs.removeAll(keepingCapacity: true)
         lock.unlock()
+        // The cadence line is ALWAYS emitted (when the window had evidence): it is the ruler the
+        // smoothness A/B reads, and it must not depend on an env var the field never sets. The
+        // verbose counters line stays behind its existing lever.
+        if let cadence {
+            let cadenceLine = String(
+                format: "pf-present judderPermille=%d modeVsync=%d n=%d stalls=%d disorder=%d",
+                cadence.judderPermille, cadence.modeUnits, cadence.samples,
+                cadence.stalls, cadence.disordered)
+            presentLog.info("\(cadenceLine, privacy: .public)")
+            if presentDebug {
+                print(cadenceLine)
+                fflush(stdout)
+            }
+        }
+        guard verbose else { return }
         // Console.app first (the on-device readout — see presentLog); stdout only under the env
         // lever (the CLI client's capture channel).
         presentLog.info("\(line, privacy: .public)")
@@ -746,6 +920,10 @@ public final class Stage2Pipeline {
     /// mirror the pump's bounded join.
     private let renderSignal = DispatchSemaphore(value: 0)
     private let vsyncClock = VsyncClock()
+    /// The per-session present statistics, retained so the clock-bearing threads can republish
+    /// the panel period the cadence statistic quantises against. Assigned once in `start`, read
+    /// from the render/link threads; the object is itself lock-guarded.
+    private var presentStats: PresentDebugStats?
     private let renderStopped = DispatchSemaphore(value: 0)
     private var renderJoinable = false
     /// Deadline pacing's staged CAMetalDisplayLink frame-rate hint (see `FrameRateHint`).
@@ -967,7 +1145,14 @@ public final class Stage2Pipeline {
         // startDeadlinePresenter. The V-Sync policy below doesn't apply there (the link deadline-
         // times every present). Deadline sessions ALWAYS carry the stats (their pf-present line
         // streams to Console.app via presentLog — the on-device pacing decomposition).
-        let debugStats = (presentDebug || pacing == .deadline) ? PresentDebugStats() : nil
+        //
+        // The stats object is now built for EVERY session, because the cadence statistic inside
+        // it has to be: a smoothness defect produces no drops and healthy percentiles, so gating
+        // it behind an env var means the one number that could see it is off exactly when it
+        // matters. `verbose` preserves the old behaviour for the wordy counters line.
+        let debugStats: PresentDebugStats? = PresentDebugStats(
+            verbose: presentDebug || pacing == .deadline)
+        presentStats = debugStats
         if pacing == .deadline {
             startDeadlinePresenter(debugStats: debugStats)
             return
@@ -1241,6 +1426,9 @@ public final class Stage2Pipeline {
     /// (their CAMetalDisplayLink's updates are both clock and retry).
     public func renderTick(targetMediaTime: CFTimeInterval, period: CFTimeInterval) {
         vsyncClock.set(target: targetMediaTime, period: period)
+        // The link's own reported period is the authoritative grid for the cadence statistic —
+        // it tracks VRR rate changes, which a mode-derived seed cannot.
+        presentStats?.setPanelPeriod(ns: Int64(period * 1_000_000_000))
         renderSignal.signal()
     }
 

clients/apple/Tests/PunktfunkKitTests/DualSenseHIDTests.swift

@@ -43,5 +43,33 @@ final class DualSenseHIDTests: XCTestCase {
         let crc = DualSenseHID.crc32(seed: UInt8(ascii: "1"), Array("23456789".utf8))
         XCTAssertEqual(crc, 0xCBF4_3926)
     }
+
+    // MARK: - Device selection (B14)
+
+    /// With two DualSenses attached, each renderer must drive its OWN device. The old code took
+    /// `Set.first` from an unordered set, so the pad→device binding was a coin flip that could
+    /// point both renderers at the same pad.
+    func testPreferredIndexHonoursAnExplicitLocation() {
+        let ids: [UInt32?] = [0x1D18_0000, 0x1420_0000, 0x1411_0000]
+        XCTAssertEqual(DualSenseHID.preferredIndex(among: ids, preferring: 0x1420_0000), 1)
+        XCTAssertEqual(DualSenseHID.preferredIndex(among: ids, preferring: 0x1D18_0000), 0)
+    }
+
+    /// No preference (or one the pad no longer has): fall back to the LOWEST id — arbitrary, but
+    /// stable across calls, which `Set.first` was not.
+    func testPreferredIndexFallsBackToTheLowestIdDeterministically() {
+        let ids: [UInt32?] = [0x1D18_0000, 0x1420_0000, 0x1411_0000]
+        XCTAssertEqual(DualSenseHID.preferredIndex(among: ids, preferring: nil), 2)
+        // A wanted id that is gone (pad unplugged between enumeration and open) must not fail the
+        // open — it degrades to the same stable fallback.
+        XCTAssertEqual(DualSenseHID.preferredIndex(among: ids, preferring: 0xDEAD_BEEF), 2)
+    }
+
+    /// A device IOKit reports no location for must never displace one it can place.
+    func testPreferredIndexSortsUnplaceableDevicesLast() {
+        XCTAssertEqual(DualSenseHID.preferredIndex(among: [nil, 0x1420_0000], preferring: nil), 1)
+        XCTAssertEqual(DualSenseHID.preferredIndex(among: [nil, nil], preferring: nil), 0)
+        XCTAssertNil(DualSenseHID.preferredIndex(among: [], preferring: nil))
+    }
 }
 #endif

clients/apple/Tests/PunktfunkKitTests/GamepadWireTests.swift

@@ -79,7 +79,7 @@ final class GamepadWireTests: XCTestCase {
         XCTAssertEqual(GamepadWire.axisRSY, UInt32(PUNKTFUNK_AXIS_RS_Y))
         XCTAssertEqual(GamepadWire.axisLT, UInt32(PUNKTFUNK_AXIS_LT))
         XCTAssertEqual(GamepadWire.axisRT, UInt32(PUNKTFUNK_AXIS_RT))
-        XCTAssertEqual(GamepadWire.maxPads, Int(MAX_PADS))
+        XCTAssertEqual(GamepadWire.maxPads, Int(PUNKTFUNK_MAX_PADS))
     }
 
     func testPadIndexRidesFlagsOnEveryPerPadEvent() {

clients/apple/Tests/PunktfunkKitTests/PresentIntervalsTests.swift

@@ -0,0 +1,170 @@
+// Parity tests for the Swift `PresentIntervals` port (Video/Stage2Pipeline.swift) against
+// `punktfunk_core::phase::PresentIntervals` — the cadence (judder) statistic of
+// design/presenter-cadence-rework.md WP1.
+//
+// These are deliberately the SAME cases and the SAME vectors as the Rust unit tests in
+// crates/punktfunk-core/src/phase.rs (module `cadence_tests`). WP1's acceptance criterion is that
+// all three clients emit the same numbers for the same synthetic input, and a hand-written port is
+// exactly where that quietly stops being true — so the port is pinned here rather than trusted.
+//
+// If you change one side, change both, and keep the vectors identical.
+
+import Foundation
+import XCTest
+
+@testable import PunktfunkKit
+
+final class PresentIntervalsTests: XCTestCase {
+    /// 120 Hz in ns — the Rust tests' `P`.
+    private static let P: Int64 = 8_333_333
+
+    /// Fold `n` presents spaced by `spacings` in rotation, starting at an arbitrary instant.
+    /// Mirrors the Rust helper of the same shape.
+    private func cadence(_ spacings: [Int64], _ n: Int, period: Int64 = P) -> PresentIntervals {
+        var pi = PresentIntervals()
+        var t: Int64 = 1_000_000_000
+        pi.record(presentNs: t, periodNs: period)
+        for i in 0..<n {
+            t += spacings[i % spacings.count]
+            pi.record(presentNs: t, periodNs: period)
+        }
+        return pi
+    }
+
+    func testARegularCadenceHasNoJudder() {
+        let s = cadence([Self.P], 60).summary()
+        XCTAssertEqual(s?.modeUnits, 1)
+        XCTAssertEqual(s?.judderPermille, 0)
+        XCTAssertEqual(s?.samples, 60)
+    }
+
+    /// The property that makes this one ruler across rates: a stream at half (or a quarter of)
+    /// the panel rate is SMOOTH, not judder — the mode absorbs the cadence ratio.
+    func testSixtyOnOneTwentyReadsSmooth() {
+        for (mult, expected) in [(Int64(2), 2), (Int64(4), 4)] {
+            let s = cadence([Self.P * mult], 40).summary()
+            XCTAssertEqual(s?.modeUnits, expected)
+            XCTAssertEqual(s?.judderPermille, 0)
+        }
+    }
+
+    /// D3's signature: the same mean spacing as a steady 2, delivered as alternating 1 and 3.
+    /// Identical average frame rate, identical latency percentiles — this is the broken-looking one.
+    ///
+    /// Also pins the TIE-BREAK. The histogram is 50/50 here, and Rust's `max_by_key` takes the
+    /// last maximum while Swift's `max(by:)` takes the first, so both sides spell the rule out:
+    /// ties resolve to the smallest spacing.
+    func testTheSawtoothThatLatencyStatsCannotSee() {
+        let s = cadence([Self.P, Self.P * 3], 40).summary()
+        XCTAssertEqual(s?.judderPermille, 500)
+        XCTAssertEqual(s?.modeUnits, 1, "a tied mode resolves to the smallest spacing")
+    }
+
+    /// Sub-refresh jitter is not judder: the display quantises it away, so the metric must too.
+    func testJitterInsideARefreshIsNotJudder() {
+        let s = cadence([Self.P + Self.P * 2 / 5, Self.P - Self.P * 2 / 5], 40).summary()
+        XCTAssertEqual(s?.modeUnits, 1)
+        XCTAssertEqual(s?.judderPermille, 0)
+    }
+
+    func testAStallIsCountedApartFromJudder() {
+        var pi = PresentIntervals()
+        var t: Int64 = 1_000_000_000
+        pi.record(presentNs: t, periodNs: Self.P)
+        for _ in 0..<20 {
+            t += Self.P
+            pi.record(presentNs: t, periodNs: Self.P)
+        }
+        t += Self.P * 400  // a pause, not a pacing defect
+        pi.record(presentNs: t, periodNs: Self.P)
+        let s = pi.summary()
+        XCTAssertEqual(s?.judderPermille, 0)
+        XCTAssertEqual(s?.stalls, 1)
+        XCTAssertEqual(s?.samples, 20)
+    }
+
+    func testOutOfOrderCallbacksDoNotCorruptTheRun() {
+        var pi = PresentIntervals()
+        var t: Int64 = 1_000_000_000
+        pi.record(presentNs: t, periodNs: Self.P)
+        for _ in 0..<10 {
+            t += Self.P
+            pi.record(presentNs: t, periodNs: Self.P)
+        }
+        pi.record(presentNs: t - Self.P * 3, periodNs: Self.P)  // a late/duplicate delivery
+        for _ in 0..<10 {
+            t += Self.P
+            pi.record(presentNs: t, periodNs: Self.P)
+        }
+        let s = pi.summary()
+        XCTAssertEqual(s?.disordered, 1)
+        XCTAssertEqual(
+            s?.judderPermille, 0,
+            "keeping the later instant means the following spacings stay on the grid")
+    }
+
+    /// The on-glass failure of 2026-08-05, pinned on both sides. A render callback can deliver a
+    /// garbage far-future timestamp on a session's first frames; holding "the later instant"
+    /// unconditionally latched onto it and scored EVERY subsequent present as disordered for the
+    /// whole session. One bad sample must cost one sample.
+    func testAGarbageFarFutureStampDoesNotWedgeTheRun() {
+        var pi = PresentIntervals()
+        var t: Int64 = 1_000_000_000
+        pi.record(presentNs: t, periodNs: Self.P)
+        pi.record(presentNs: t + 60 * 60 * 1_000_000_000, periodNs: Self.P)
+        for _ in 0..<20 {
+            t += Self.P
+            pi.record(presentNs: t, periodNs: Self.P)
+        }
+        let s = pi.summary()
+        XCTAssertEqual(s?.disordered, 1, "the garbage stamp cost exactly one sample")
+        XCTAssertEqual(s?.modeUnits, 1)
+        XCTAssertEqual(s?.judderPermille, 0)
+        XCTAssertEqual(s?.samples, 19, "every present after the re-anchor scored")
+    }
+
+    func testAnUnknownGridScoresNothing() {
+        var pi = PresentIntervals()
+        var t: Int64 = 1_000_000_000
+        for _ in 0..<60 {
+            t += Self.P
+            pi.record(presentNs: t, periodNs: 0)  // no learned period yet
+        }
+        XCTAssertNil(pi.summary())
+        XCTAssertNotNil(cadence([Self.P], 60).summary(), "control")
+    }
+
+    func testAShortWindowPublishesNothing() {
+        XCTAssertNil(cadence([Self.P], 5).summary())
+    }
+
+    /// The cadence continues across a window boundary — dropping the predecessor on drain would
+    /// silently discard one interval per window, every window.
+    func testTakeResetsTheCountsButNotTheCadence() {
+        var pi = cadence([Self.P], 20)
+        XCTAssertNotNil(pi.take())
+        XCTAssertNil(pi.summary(), "counts cleared")
+        var t: Int64 = 1_000_000_000 + Self.P * 20
+        for _ in 0..<10 {
+            t += Self.P
+            pi.record(presentNs: t, periodNs: Self.P)
+        }
+        XCTAssertEqual(
+            pi.summary()?.samples, 10,
+            "the first post-drain present scored against the pre-drain one")
+    }
+
+    func testSplitForgetsThePredecessor() {
+        var pi = cadence([Self.P], 20)
+        _ = pi.take()
+        pi.split()
+        var t: Int64 = 5_000_000_000  // a discontinuity: the gap across it is meaningless
+        for _ in 0..<10 {
+            t += Self.P
+            pi.record(presentNs: t, periodNs: Self.P)
+        }
+        let s = pi.summary()
+        XCTAssertEqual(s?.samples, 9)
+        XCTAssertEqual(s?.stalls, 0, "the gap was not scored at all")
+    }
+}

clients/apple/Tests/PunktfunkKitTests/RumbleTuningTests.swift

@@ -56,7 +56,7 @@ final class RumbleTuningTests: XCTestCase {
     /// storm, an audible target left to the ticker (watchdog path), then `stop()` — which runs
     /// `queue.sync` against the same serial queue the ticker fires on and must not deadlock.
     func testRendererSurvivesCallStormAndTeardownWithoutController() {
-        let renderer = RumbleRenderer(policy: .session)
+        let renderer = RumbleRenderer()
         renderer.retarget(nil)
         for i in 0..<500 {
             renderer.apply(
@@ -72,7 +72,7 @@ final class RumbleTuningTests: XCTestCase {
     /// every policy stop (lease expiry, legacy staleness, session close), and the renderer's only
     /// job is to apply them. Drive the real queue/ticker (no physical pad) and confirm no wedge.
     func testZeroCommandSilencesAndTeardownDoesNotDeadlock() {
-        let renderer = RumbleRenderer(policy: .session)
+        let renderer = RumbleRenderer()
         renderer.retarget(nil)
         renderer.apply(low: 0x8000, high: 0x8000)
         Thread.sleep(forTimeInterval: 0.1)

clients/session/src/main.rs

@@ -286,6 +286,12 @@ mod session_main {
         // Spawned at first params-build so it exists for --connect AND console launches.
         #[cfg(unix)]
         crate::ctl_socket::spawn(gamepad.clone());
+        // Pad-audio prefs to OUR gamepad service (same reasoning as the pin above): tier-A
+        // slots declare their render caps at open time, which happens on attach — after this.
+        gamepad.set_pad_audio_prefs(
+            settings.pad_haptics,
+            pf_client_core::pad_audio::speaker_active(&settings.pad_speaker),
+        );
         let mode = Mode {
             width: if settings.width == 0 {
                 native.width
@@ -389,6 +395,11 @@ mod session_main {
             cursor_forward: settings.mouse_mode() == trust::MouseMode::Desktop,
             mic_enabled: settings.mic_enabled,
             echo_cancel: settings.echo_cancel,
+            // Pad audio (0xD1): the DualSense haptics/speaker render settings. The gamepad
+            // service learns the same prefs below so tier-A slots declare their render caps
+            // at open; the session pump gates CLIENT_CAP_PAD_AUDIO + the renderer on these.
+            pad_haptics: settings.pad_haptics,
+            pad_speaker: settings.pad_speaker.clone(),
             clipboard,
             // The Settings preference (auto → VAAPI where it exists; the presenter
             // demotes to software on boxes whose Vulkan can't import the dmabufs).

crates/pf-client-core/Cargo.toml

@@ -57,6 +57,10 @@ sdl3 = { version = "0.18", features = ["hidapi"] }
 
 [target.'cfg(windows)'.dependencies]
 wasapi = "0.23"
+# Pad-audio correlation (pad_audio.rs): the HID devnode's ContainerID and a render endpoint's
+# stamped PKEY_Device_ContainerId both live in the registry — read-only, which sidesteps COM
+# property stores entirely (the same version the host pins).
+winreg = "0.56"
 sdl3 = { version = "0.18", features = ["hidapi", "build-from-source"] }
 # D3D11VA decode (video_d3d11.rs): device/adapter selection, DXVA probes, and the shared
 # NT-handle hand-off ring. Same pinned rev as clients/windows so the workspace builds ONE

crates/pf-client-core/src/audio_wasapi.rs

@@ -98,13 +98,43 @@ pub fn devices() -> Result<(Vec<AudioDevice>, Vec<AudioDevice>)> {
 /// Settings device pickers via session main), or the OS default. A picked device that's
 /// gone (unplugged USB DAC, remote session) falls back to the default with a warning —
 /// audio keeps working, like the PipeWire twin's `target.object` behavior.
+/// Resolve an active endpoint by id WITHOUT `DeviceEnumerator::get_device`.
+///
+/// That helper builds its argument as `PCWSTR::from_raw(HSTRING::from(id).as_ptr())` — the
+/// `HSTRING` is a temporary, dropped at the end of that statement, so `GetDevice` reads freed
+/// memory and misses ids that are perfectly valid. Scanning the active collection touches only
+/// safe crate APIs, so it cannot regress the same way. (`punktfunk-host` fixes the same bug with
+/// raw COM instead; this crate cannot, because it pins a different `windows` revision than
+/// `wasapi` does, making the two `IMMDevice` types incompatible.)
+pub(crate) fn device_by_id(
+    enumerator: &DeviceEnumerator,
+    direction: &Direction,
+    id: &str,
+) -> Result<wasapi::Device> {
+    let devices = enumerator
+        .get_device_collection(direction)
+        .map_err(|e| anyhow!("enumerate {direction:?} endpoints: {e}"))?;
+    let count = devices
+        .get_nbr_devices()
+        .map_err(|e| anyhow!("endpoint count: {e}"))?;
+    for i in 0..count {
+        let dev = devices
+            .get_device_at_index(i)
+            .map_err(|e| anyhow!("endpoint {i}: {e}"))?;
+        if dev.get_id().is_ok_and(|got| got == id) {
+            return Ok(dev);
+        }
+    }
+    anyhow::bail!("no active {direction:?} endpoint with id {id}")
+}
+
 fn pick_device(
     enumerator: &DeviceEnumerator,
     direction: &Direction,
     var: &str,
 ) -> Result<wasapi::Device> {
     if let Some(id) = std::env::var(var).ok().filter(|v| !v.is_empty()) {
-        match enumerator.get_device(&id) {
+        match device_by_id(enumerator, direction, &id) {
             Ok(d) => {
                 tracing::info!(
                     var,

crates/pf-client-core/src/gamepad.rs

@@ -302,6 +302,21 @@ fn set_valve_hidapi(enabled: bool) {
     sdl3::hint::set("SDL_JOYSTICK_HIDAPI_STEAM", v);
 }
 
+/// Disable the Valve HIDAPI drivers **before SDL exists** — call this alongside the other
+/// pre-`SDL_Init` hints, not after a subsystem is up.
+///
+/// The damage these drivers do happens at *enumeration*, which is part of initialising the
+/// joystick/gamepad subsystem. Setting the hint afterwards does detach the driver, but only after
+/// it has already sent the Deck its `ID_CLEAR_DIGITAL_MAPPINGS` + `TRACKPAD_NONE` — so the
+/// built-in trackpad-mouse dies system-wide and stays dead until the firmware watchdog restores
+/// lizard mode seconds later. The threaded worker ([`run`]) has always done this in the right
+/// order; the caller-pumped path could not, because by the time it receives a
+/// [`sdl3::GamepadSubsystem`] the enumeration has already happened. Hence a separate entry point
+/// its callers can put in the right place.
+pub fn preinit_disable_valve_hidapi() {
+    set_valve_hidapi(false);
+}
+
 /// Map the SDL-reported controller type to the virtual pad we'd ask the host to create.
 fn pref_for_type(t: sdl3::gamepad::GamepadType) -> GamepadPref {
     use sdl3::gamepad::GamepadType as T;
@@ -354,8 +369,14 @@ enum Ctl {
     Pin(Option<String>),
     KindOverride(GamepadPref),
     Forwarding(bool),
-    SystemButtons { forward_raw: bool, gesture: bool },
+    SystemButtons {
+        forward_raw: bool,
+        gesture: bool,
+    },
     TapButton(u32),
+    /// Which pad-audio streams the session's settings want rendered (bit0 = haptics, bit1 =
+    /// speaker) — the settings half of the per-pad tier-A capability declared at slot open.
+    PadAudioPrefs(u8),
     MenuMode(bool),
     MenuRumble(MenuPulse),
 }
@@ -412,9 +433,12 @@ impl GamepadService {
     /// and calls [`GamepadPump::tick`] once per loop iteration (the threaded worker's
     /// per-wakeup work: ctl drain, chord-hold check, menu repeat, feedback).
     ///
-    /// Like the threaded worker, this disables the Valve HIDAPI drivers up front (their
-    /// mere enumeration kills the Deck's trackpad-mouse system-wide); they are enabled
-    /// for the duration of an attached session only.
+    /// The Valve HIDAPI drivers are held off here too, but this is **too late to be the only
+    /// place it happens**: the `subsystem` argument means enumeration is already done, and that
+    /// is when the Deck driver kills the trackpad-mouse. The caller must also call
+    /// [`preinit_disable_valve_hidapi`] with its other pre-`SDL_Init` hints. This call still
+    /// earns its place — it re-asserts "off" for a process that ran a session earlier — but on
+    /// its own it only detaches a driver that has already done the damage.
     pub fn pumped(subsystem: sdl3::GamepadSubsystem) -> (GamepadService, GamepadPump) {
         set_valve_hidapi(false);
         let pads = Arc::new(Mutex::new(Vec::new()));
@@ -555,6 +579,18 @@ impl GamepadService {
         let _ = self.ctl.send(Ctl::TapButton(wire::BTN_MISC1));
     }
 
+    /// Declare which pad-audio streams this session's settings want rendered (`haptics` =
+    /// [`Settings::pad_haptics`](crate::trust::Settings::pad_haptics), `speaker` =
+    /// `pad_speaker == "pad"` via [`crate::pad_audio::speaker_active`]). Drives the per-pad
+    /// tier-A capability bits declared to the core at slot open — a WIRED DualSense/Edge
+    /// declares exactly these; every other pad declares 0. Call before [`Self::attach`],
+    /// like [`Self::set_kind_override`]: slots declare at open time. Defaults to "nothing"
+    /// for an embedder that never calls it, keeping the wire bytes exactly as before.
+    pub fn set_pad_audio_prefs(&self, haptics: bool, speaker: bool) {
+        let bits = (haptics as u8) | ((speaker as u8) << 1);
+        let _ = self.ctl.send(Ctl::PadAudioPrefs(bits));
+    }
+
     pub fn attach(&self, connector: Arc<NativeClient>) {
         let _ = self.ctl.send(Ctl::Attach(connector));
     }
@@ -609,6 +645,38 @@ impl GamepadPump {
         self.worker.menu_poll();
         self.worker.render_feedback();
     }
+
+    /// Close every forwarded slot — flush its held wire state, tell the host to remove the pad,
+    /// and physically silence it. Call once on the way out of the caller's event loop.
+    ///
+    /// [`GamepadService::detach`] only *posts* `Ctl::Detach`; the close — the flush, the host-side
+    /// `GamepadRemove`, and the explicit `set_rumble(0, 0)` backstop in `close_slot_at` — happens
+    /// when the pump next drains it. An exit path that detached and then left the loop without
+    /// another [`tick`](Self::tick) therefore skipped all of it, and nothing else would: the slots
+    /// hold no `Drop` that silences them. A pad left mid-buzz stayed buzzing.
+    ///
+    /// This closes the slots directly rather than draining the queued `Ctl::Detach` that would
+    /// have done it. Same physical outcome by a shorter path, and deliberately so: this also runs
+    /// from `Drop`, and `drain_ctl` reaches `Mutex::lock().unwrap()`, which on a poisoned lock
+    /// would panic — during an unwind that aborts the process. Closing a slot touches no lock.
+    ///
+    /// Idempotent, and safe with nothing attached.
+    pub fn shutdown(&mut self) {
+        self.worker.close_all_slots();
+    }
+}
+
+/// The silence backstop of last resort. A caller's loop can also leave by `?` on a fatal overlay
+/// or present error — several paths do — and those would skip an explicit
+/// [`shutdown`](GamepadPump::shutdown) entirely, leaving a forwarded pad buzzing on the way out.
+///
+/// Callers should still call `shutdown` at their normal exit rather than lean on this: the pad
+/// wants to go quiet *before* a long teardown (session join, `vkDeviceWaitIdle`), not after it.
+/// Doing both is free — `shutdown` is idempotent.
+impl Drop for GamepadPump {
+    fn drop(&mut self) {
+        self.shutdown();
+    }
 }
 
 /// The lowest wire pad index (0..[`MAX_PADS`](punktfunk_core::input::MAX_PADS)) not already held
@@ -682,13 +750,29 @@ fn axis_value(axis: sdl3::gamepad::Axis, v: i16) -> (u32, i32) {
 /// host parses off its virtual pad; the wire's 11-byte trigger blocks drop in verbatim.
 /// Enable bits select only the fields each update touches, so rumble (driven separately
 /// through SDL) and untouched fields keep their state.
+///
+/// The offsets below are the USB output report's, **minus one**: SDL's payload carries no leading
+/// report id. `pf-inject`'s `dualsense_proto::out_report` is where that layout is written down and
+/// explained (including the Bluetooth `+2` base), but this crate cannot import it — `pf-inject` is
+/// host-side and neither crate depends on the other, and a DualSense report layout has no business
+/// in `punktfunk-core`, the only crate they share. So this is a deliberate second copy, and
+/// [`ds5_offsets_track_the_usb_report`](ds5_feedback_tests) pins the `−1` relationship rather than
+/// leaving it to a comment.
 struct Ds5Feedback;
 
 impl Ds5Feedback {
-    const RIGHT_TRIGGER: usize = 10;
-    const LEFT_TRIGGER: usize = 21;
-    const PAD_LIGHTS: usize = 43;
-    const LED_RGB: usize = 44;
+    /// The USB report offsets these are derived from — see the type doc. Kept beside the derived
+    /// values so the subtraction is visible at the point of definition.
+    const REPORT_ID_LEN: usize = 1;
+    /// The audio-control region (`ucHeadphoneVolume`…`ucAudioMuteBits`): report byte 5.
+    const AUDIO: usize = 5 - Self::REPORT_ID_LEN;
+    const RIGHT_TRIGGER: usize = 11 - Self::REPORT_ID_LEN;
+    const LEFT_TRIGGER: usize = 22 - Self::REPORT_ID_LEN;
+    const PAD_LIGHTS: usize = 44 - Self::REPORT_ID_LEN;
+    const LED_RGB: usize = 45 - Self::REPORT_ID_LEN;
+    /// One adaptive-trigger parameter block: a mode byte plus 10 parameters. Mirrors
+    /// `PUNKTFUNK_HID_EFFECT_MAX`, which is the same number at the C-ABI boundary.
+    const TRIGGER_LEN: usize = punktfunk_core::abi::PUNKTFUNK_HID_EFFECT_MAX as usize;
 
     fn trigger_packet(which: u8, effect: &[u8]) -> [u8; 47] {
         let mut p = [0u8; 47];
@@ -698,7 +782,7 @@ impl Ds5Feedback {
             (0x08, Self::LEFT_TRIGGER)
         };
         p[0] = flag;
-        let n = effect.len().min(11);
+        let n = effect.len().min(Self::TRIGGER_LEN);
         p[off..off + n].copy_from_slice(&effect[..n]);
         p
     }
@@ -718,6 +802,29 @@ impl Ds5Feedback {
         p[Self::PAD_LIGHTS] = bits & 0x1F;
         p
     }
+
+    /// The one-shot tier-A activation packet — the SDL disable-bit trap undone. `p[0]`
+    /// (`ucEnableBits1`) bit0 = "enable rumble emulation" and bit1 = "disable audio haptics"
+    /// (SDL_hidapi_ps5.c); SDL sets BOTH whenever its rumble path runs, which mutes the very
+    /// voice coils the 0xD1 haptics stream drives. Per SDL's own comment — "Leaving emulated
+    /// rumble bits off will restore audio haptics" — a packet with those bits CLEARED (and no
+    /// other valid flag, so nothing else is touched) puts the pad back on audio haptics.
+    fn audio_haptics_packet() -> [u8; 47] {
+        [0u8; 47]
+    }
+
+    /// Fold a host [`HidOutput::AudioCtl`] into an effects packet: `raw` is DS5 output report
+    /// `0x02` bytes 5..=10 verbatim → struct offsets 4..=9 ([`Self::AUDIO`] — headphone/
+    /// speaker/mic volumes + routing), and `p[0]` re-asserts the report's audio-valid flags
+    /// (`flags` bits1..4 = report `flag0` bits 4..7). `flags` bit0 (haptics-select, `flag0`
+    /// bit1 = SDL's "disable audio haptics") is deliberately NOT replayed: bits 0/1 stay
+    /// clear so the pad's audio haptics stay live (see [`audio_haptics_packet`]).
+    fn audio_ctl_packet(flags: u8, raw: &[u8; 6]) -> [u8; 47] {
+        let mut p = [0u8; 47];
+        p[0] = (flags & 0x1E) << 3;
+        p[Self::AUDIO..Self::AUDIO + 6].copy_from_slice(raw);
+        p
+    }
 }
 
 /// One forwarded controller during an attached session: the open SDL handle, its stable wire
@@ -754,6 +861,14 @@ struct Slot {
     /// Hold-Select→guide state ([`SelectGesture`]) — only fed while the worker's
     /// `guide_gesture` policy is on.
     gesture: SelectGesture,
+    /// Pad-audio render capabilities declared for this slot (bit0 = haptics, bit1 = speaker
+    /// — the [`NativeClient::set_pad_audio_caps`] bits). Nonzero only for a tier-A pad (a
+    /// WIRED DualSense/Edge, see [`crate::pad_audio::is_tier_a_ds5`]) under matching
+    /// settings; bit0 set additionally suppresses wire rumble for this slot (the SDL
+    /// disable-bit trap — see [`Worker::render_feedback`]).
+    audio_caps: u8,
+    /// The wire-rumble-suppressed notice fired for this slot (log once, not per command).
+    rumble_suppressed_logged: bool,
 }
 
 impl Slot {
@@ -770,6 +885,8 @@ impl Slot {
             held_clicks: [false; 2],
             last_accel: [0; 3],
             gesture: SelectGesture::default(),
+            audio_caps: 0,
+            rumble_suppressed_logged: false,
         }
     }
 
@@ -907,6 +1024,10 @@ struct Worker {
     /// Releases owed for synthetic taps ([`Ctl::TapButton`]): `(pad, bit, due)` — the
     /// down went out on receipt, the up goes out from the poll once `due` passes.
     synthetic_ups: Vec<(u8, u32, Instant)>,
+    /// Pad-audio streams the session's settings want rendered (bit0 = haptics, bit1 =
+    /// speaker — [`GamepadService::set_pad_audio_prefs`]). `0` (the default) until an embedder
+    /// declares some: tier-A detection then never runs and every arrival stays caps-less.
+    pad_audio_prefs: u8,
     attached: Option<Arc<NativeClient>>,
     /// Raises the UI escape signal; the escape chord fires it once per press.
     escape_tx: async_channel::Sender<()>,
@@ -1112,11 +1233,18 @@ impl Worker {
             Ok(pad) => {
                 let mut slot = Slot::new(id, index, pref, pad);
                 Self::set_slot_sensors(&mut slot, true);
+                slot.audio_caps = self.pad_audio_caps_for(id, &slot.pad);
                 // Declare this pad's kind BEFORE any of its input, so the host builds a matching
                 // virtual device (mixed types — pad 0 a DualSense, pad 1 an Xbox pad). The core
                 // re-sends it a few times against datagram loss; an older host ignores it and
                 // uses the session-default kind.
                 if let Some(c) = &self.attached {
+                    // Pad-audio render caps go in FIRST — the core ORs them into this (and
+                    // every re-sent) arrival's flags bits 8/9 toward a capable host. ALWAYS
+                    // set (0 for non-tier-A): wire indices are reused within a connection, so
+                    // a tier-A slot that closes must not leave its bits behind for the next
+                    // pad on the same index (the set_rumble_quirks rule).
+                    c.set_pad_audio_caps(index, slot.audio_caps);
                     send(
                         c,
                         InputKind::GamepadArrival,
@@ -1139,6 +1267,27 @@ impl Worker {
                     };
                     c.set_rumble_quirks(index as u16, quirks);
                 }
+                if slot.audio_caps != 0 {
+                    if slot.audio_caps & 0x01 != 0 {
+                        // Tier-A haptics activation: the SDL disable-bit trap. SDL's DS5
+                        // driver sets ucEnableBits1 0x01|0x02 ("enable rumble emulation" +
+                        // "disable audio haptics") whenever its rumble path runs — which
+                        // would MUTE the voice coils the 0xD1 stream drives. One effects
+                        // packet with those bits CLEARED puts the pad back on audio haptics
+                        // ("Leaving emulated rumble bits off will restore audio haptics" —
+                        // SDL_hidapi_ps5.c); wire rumble for this slot is suppressed in
+                        // render_feedback so SDL never re-arms them.
+                        let _ = slot.pad.send_effect(&Ds5Feedback::audio_haptics_packet());
+                    }
+                    // Hand the pad to the session's renderer worker. Windows correlation
+                    // needs the HID interface path; Linux matches the sink by signature.
+                    crate::pad_audio::register_tier_a(index, slot.pad.path());
+                    tracing::info!(
+                        index,
+                        caps = slot.audio_caps,
+                        "tier-A DualSense: pad-audio render caps declared"
+                    );
+                }
                 tracing::info!(
                     id,
                     index,
@@ -1152,6 +1301,35 @@ impl Worker {
         }
     }
 
+    /// This pad's pad-audio render capabilities (the bits [`NativeClient::set_pad_audio_caps`]
+    /// takes): the settings prefs for a tier-A pad — a physical DualSense/Edge (by VID:PID,
+    /// never the DECLARED kind: the stream renders on the controller in the user's hands) on
+    /// a WIRED connection — and `0` for everything else (tier B/C are out of scope). Wired
+    /// comes from `SDL_GetGamepadConnectionState`; when SDL answers Unknown, the pad's 4-ch
+    /// audio sibling existing is the fallback signal (Bluetooth exposes no audio device).
+    fn pad_audio_caps_for(&self, id: u32, pad: &sdl3::gamepad::Gamepad) -> u8 {
+        if self.pad_audio_prefs == 0 {
+            return 0; // nothing wanted — skip the (possibly probing) wired check entirely
+        }
+        let jid = sdl3::sys::joystick::SDL_JoystickID(id);
+        let vid = self.subsystem.vendor_for_id(jid).unwrap_or(0);
+        let pid = self.subsystem.product_for_id(jid).unwrap_or(0);
+        if !crate::pad_audio::is_tier_a_ds5(vid, pid, true) {
+            return 0; // not a DualSense/Edge — no wired check needed
+        }
+        use sdl3::joystick::ConnectionState;
+        let wired = match pad.connection_state() {
+            Ok(ConnectionState::Wired) => true,
+            Ok(ConnectionState::Wireless) => false,
+            _ => crate::pad_audio::wired_audio_sibling(pad.path().as_deref()),
+        };
+        if crate::pad_audio::is_tier_a_ds5(vid, pid, wired) {
+            self.pad_audio_prefs
+        } else {
+            0
+        }
+    }
+
     /// Flush a slot's held wire state (so nothing sticks down host-side) and drop it — closing
     /// the SDL handle. The flush only emits wire events, so it is safe even when the device is
     /// already gone (unplug).
@@ -1160,6 +1338,7 @@ impl Worker {
         // unplug) must not depend on what SDL does to a rumbling device at close. Errors are
         // expected for an already-unplugged pad.
         let _ = self.slots[i].pad.set_rumble(0, 0, 100);
+        Self::reset_slot_feedback(&mut self.slots[i]);
         if let Some(c) = self.attached.clone() {
             Self::flush_slot(&c, &mut self.slots[i]);
             // Signal the host to tear down this pad's virtual device (native hot-unplug). Sent
@@ -1168,6 +1347,11 @@ impl Worker {
             send(&c, InputKind::GamepadRemove, 0, 0, self.slots[i].index);
         }
         let slot = self.slots.remove(i);
+        if slot.audio_caps != 0 {
+            // Take the pad back from the pad-audio renderer (its device-gone path then
+            // re-correlates — and finds nothing until a tier-A pad registers again).
+            crate::pad_audio::unregister_tier_a(slot.index);
+        }
         tracing::info!(
             id = slot.id,
             index = slot.index,
@@ -1175,6 +1359,35 @@ impl Worker {
         );
     }
 
+    /// Hand the physical controller back in a neutral state before its handle closes.
+    ///
+    /// Rumble stops on its own the moment nothing renews it, but the rich planes do not: an
+    /// adaptive-trigger effect and a lightbar colour are LATCHED in the pad's firmware and survive
+    /// the stream, the app, and being unplugged. Ending a session on a weapon's trigger resistance
+    /// left the physical trigger stiff on the desktop afterwards, with nothing to clear it but
+    /// another game. Apple's client already resets on teardown; this is the desktop half.
+    ///
+    /// Best-effort throughout: the pad may already be gone (that is one of the ways we get here).
+    fn reset_slot_feedback(slot: &mut Slot) {
+        if matches!(
+            slot.pref,
+            GamepadPref::DualSense | GamepadPref::DualSenseEdge
+        ) {
+            // An all-zero trigger block is mode 0x00 — no effect — which is what releases the
+            // trigger. Both sides, then the lightbar dark and the player indicator clear.
+            for which in [0u8, 1] {
+                let _ = slot
+                    .pad
+                    .send_effect(&Ds5Feedback::trigger_packet(which, &[0u8; 11]));
+            }
+            let _ = slot.pad.send_effect(&Ds5Feedback::lightbar_packet(0, 0, 0));
+            let _ = slot.pad.send_effect(&Ds5Feedback::player_packet(0));
+        } else {
+            // Anything else with an LED goes dark through SDL, which owns the per-device details.
+            let _ = slot.pad.set_led(0, 0, 0);
+        }
+    }
+
     fn close_all_slots(&mut self) {
         while !self.slots.is_empty() {
             self.close_slot_at(0);
@@ -1560,6 +1773,7 @@ impl Worker {
                         set_valve_hidapi(false);
                     }
                 }
+                Ok(Ctl::PadAudioPrefs(bits)) => self.pad_audio_prefs = bits & 0x03,
                 Ok(Ctl::MenuMode(on)) => {
                     self.menu_mode = on;
                     if on {
@@ -1837,7 +2051,12 @@ impl Worker {
         let dur_ms: u32 = if (low, high) == (0, 0) {
             100 // a stop takes effect immediately; the duration is irrelevant
         } else {
-            backstop_ms.max(160) // floor: a jittered renewal can never gap the actuator
+            // No local floor. There was a `.max(160)` here, and it could never do anything: the
+            // engine's own `backstop()` returns `(2 * ttl).clamp(500, 5000)` or the 2000 ms legacy
+            // value, so a non-zero command's backstop is never below 500. A floor that belongs to a
+            // particular actuator belongs in its `ActuatorQuirks::min_pulse_ms`, which the engine
+            // already applies — not re-invented per renderer where it can silently disagree.
+            backstop_ms
         };
         // Surface a failed SDL rumble write: a swallowed error here (DualSense not in the right
         // HIDAPI mode, etc.) reads exactly like "rumble doesn't work". The host logs the send side
@@ -1867,6 +2086,20 @@ impl Worker {
         // first; the physical silence backstop is in `close_slot_at`).
         while let Ok(cmd) = connector.next_rumble_command(Duration::ZERO) {
             if let Some(slot) = self.slots.iter_mut().find(|s| s.index as u16 == cmd.pad) {
+                // The SDL disable-bit trap: ANY SDL rumble write sets ucEnableBits1
+                // 0x01|0x02, muting the very voice coils the 0xD1 haptics stream drives —
+                // so a slot with tier-A haptics active never issues wire rumble (the stream
+                // carries the feedback; the game's rumble is in its haptics mix).
+                if slot.audio_caps & 0x01 != 0 {
+                    if !slot.rumble_suppressed_logged {
+                        slot.rumble_suppressed_logged = true;
+                        tracing::info!(
+                            pad = slot.index,
+                            "wire rumble suppressed — the pad-audio haptics stream carries feedback"
+                        );
+                    }
+                    continue;
+                }
                 Self::issue_rumble(slot, cmd.low, cmd.high, cmd.backstop_ms);
             }
         }
@@ -1892,6 +2125,11 @@ impl Worker {
                 HidOutput::PlayerLeds { bits, .. } if is_ds => {
                     let _ = slot.pad.send_effect(&Ds5Feedback::player_packet(bits));
                 }
+                // Every other pad with player LEDs gets them through SDL, which owns the
+                // per-device pattern. This used to fall through and do nothing at all.
+                HidOutput::PlayerLeds { bits, .. } => {
+                    let _ = set_player_leds(&slot.pad, bits);
+                }
                 HidOutput::Trigger {
                     which, ref effect, ..
                 } if is_ds => {
@@ -1899,12 +2137,57 @@ impl Worker {
                         .pad
                         .send_effect(&Ds5Feedback::trigger_packet(which, effect));
                 }
-                _ => {}
+                // The audio-control region of a DS5 output report a game wrote host-side
+                // (volumes + routing; the SAMPLES ride 0xD1) — folded back into the physical
+                // pad's effects packet, but only where a tier-A renderer is actually live
+                // (`audio_caps`): replaying speaker volumes at a pad whose audio device
+                // nothing streams to would just mute/blast a future session's start state.
+                // Non-tier-A pads keep dropping it (the pre-pad-audio behaviour).
+                HidOutput::AudioCtl { flags, raw, .. } if is_ds && slot.audio_caps != 0 => {
+                    let _ = slot
+                        .pad
+                        .send_effect(&Ds5Feedback::audio_ctl_packet(flags, &raw));
+                }
+                // Deliberately unhandled, listed rather than left to a bare `_` so a new
+                // variant cannot join them silently: adaptive triggers exist only on a
+                // DualSense, and the trackpad-haptic / raw-passthrough planes are DS-specific
+                // and carried by `send_effect` above when the pad is one. `AudioCtl` lands here
+                // only when the guarded arm above declined it — a non-DualSense pad, or one with
+                // no live tier-A renderer — which is the pre-pad-audio behaviour: drop it.
+                HidOutput::Trigger { .. }
+                | HidOutput::TrackpadHaptic { .. }
+                | HidOutput::HidRaw { .. }
+                | HidOutput::AudioCtl { .. } => {}
             }
         }
     }
 }
 
+/// The SDL player index for the wire's positional player-LED `bits`, or `None` for "no player".
+///
+/// The wire carries a bitmask — one bit per LED, low 5 — while SDL wants a player *index* and owns
+/// the per-device pattern. The count bridges them: every convention that reaches this wire spells
+/// "player N" as N lit LEDs, both the DualSense patterns (`0x04`, `0x0A`, `0x15`, `0x1B`, `0x1F`)
+/// and the Switch/XInput run of low bits (`0x01`, `0x03`, `0x07`, `0x0F`). SDL's index is 0-based,
+/// so player 1 is index 0; no lit LED means *no* player rather than player 0.
+///
+/// Split out from [`set_player_leds`] so the mapping is testable — an `sdl3::Gamepad` needs a real
+/// device, so nothing that takes one can be.
+fn player_index_from_bits(bits: u8) -> Option<u16> {
+    match (bits & 0x1F).count_ones() {
+        0 => None,
+        n => Some((n - 1) as u16),
+    }
+}
+
+/// Drive a non-DualSense pad's player LEDs from the wire's positional `bits`.
+fn set_player_leds(pad: &sdl3::gamepad::Gamepad, bits: u8) -> Result<(), sdl3::Error> {
+    match player_index_from_bits(bits) {
+        None => pad.unset_player_index(),
+        Some(i) => pad.set_player_index(i),
+    }
+}
+
 /// The wire pad index a [`HidOutput`] is addressed to (every variant carries `pad`).
 fn hidout_pad(h: &HidOutput) -> u8 {
     match h {
@@ -1913,6 +2196,9 @@ fn hidout_pad(h: &HidOutput) -> u8 {
         | HidOutput::Trigger { pad, .. }
         | HidOutput::TrackpadHaptic { pad, .. }
         | HidOutput::HidRaw { pad, .. } => *pad,
+        // AudioCtl's pad is the plane's only u16. `HidOutput::decode` rejects anything at or
+        // above MAX_PADS (B27), so by the time one reaches here the narrowing is lossless.
+        HidOutput::AudioCtl { pad, .. } => *pad as u8,
     }
 }
 
@@ -1940,6 +2226,7 @@ impl Worker {
             system_forward: true,
             guide_gesture: false,
             synthetic_ups: Vec::new(),
+            pad_audio_prefs: 0,
             attached: None,
             escape_tx,
             disconnect_tx,
@@ -2385,5 +2672,254 @@ mod slot_tests {
             }),
             6
         );
+        // AudioCtl's wire pad is u16; the index space is 0..MAX_PADS end to end.
+        assert_eq!(
+            hidout_pad(&HidOutput::AudioCtl {
+                pad: 7,
+                flags: 0,
+                raw: [0; 6]
+            }),
+            7
+        );
+    }
+
+    /// The AudioCtl fold: the 6 raw bytes (DS5 report 0x02 bytes 5..=10) land at effect-struct
+    /// offsets 4..=9, the report's audio-valid flags (AudioCtl.flags bits1..4) come back as
+    /// p[0] bits 4..7, and the rumble-emulation / disable-audio-haptics bits (p[0] bits 0/1)
+    /// stay CLEAR — setting either would mute the voice coils the 0xD1 stream drives.
+    #[test]
+    fn audio_ctl_folds_report_bytes_into_effect_offsets() {
+        let raw = [0x50, 0x60, 0x70, 0x05, 0x11, 0x22];
+        // flags 0b1_0111: haptics-select (bit0) + audio-valid bits 1/2/4 of the condensed form.
+        let p = Ds5Feedback::audio_ctl_packet(0b1_0111, &raw);
+        assert_eq!(&p[4..10], &raw, "report bytes 5..=10 → struct 4..=9");
+        // bits1..4 (0b1011) → flag0 bits 4..7.
+        assert_eq!(p[0], 0b1011_0000);
+        assert_eq!(
+            p[0] & 0x03,
+            0,
+            "haptics-select must NOT replay into p[0] bits 0/1"
+        );
+        // Nothing else is touched: no trigger/LED enable bits, no stray bytes.
+        assert!(p[1..4].iter().all(|&b| b == 0));
+        assert!(p[10..].iter().all(|&b| b == 0));
+        // No audio-valid flags condenses to no enable bits (raw still carried verbatim).
+        let p = Ds5Feedback::audio_ctl_packet(0b0_0001, &raw);
+        assert_eq!(p[0], 0);
+        assert_eq!(&p[4..10], &raw);
+        // The tier-A activation packet is the all-clear: every enable bit off — per
+        // SDL_hidapi_ps5.c, leaving the emulated-rumble bits off restores audio haptics.
+        assert_eq!(Ds5Feedback::audio_haptics_packet(), [0u8; 47]);
+    }
+}
+
+/// [`Ds5Feedback`]'s three packet builders. The host-side parser, the Android writer and the Apple
+/// writer are all pinned by their own suites; this writer had nothing, despite being the one that
+/// hand-shifts every offset by the report-id length.
+#[cfg(test)]
+mod ds5_feedback_tests {
+    use super::*;
+
+    /// The USB output report offsets, written out independently of the implementation. A DS5
+    /// effects payload is the same block with the leading report id removed, so every offset is
+    /// exactly one lower — this is the relationship the derived constants encode.
+    #[test]
+    fn ds5_offsets_track_the_usb_report() {
+        for (usb, payload) in [
+            (11usize, Ds5Feedback::RIGHT_TRIGGER),
+            (22, Ds5Feedback::LEFT_TRIGGER),
+            (44, Ds5Feedback::PAD_LIGHTS),
+            (45, Ds5Feedback::LED_RGB),
+        ] {
+            assert_eq!(payload, usb - 1, "payload offset for USB byte {usb}");
+        }
+        assert_eq!(Ds5Feedback::TRIGGER_LEN, 11);
+    }
+
+    #[test]
+    fn lightbar_sets_only_its_enable_bit_and_its_three_bytes() {
+        let p = Ds5Feedback::lightbar_packet(0x11, 0x22, 0x33);
+        assert_eq!(p.len(), 47);
+        assert_eq!(p[1], 0x04, "valid_flag1 lightbar bit");
+        assert_eq!(p[0], 0, "must not claim any valid_flag0 field");
+        assert_eq!(
+            (
+                p[Ds5Feedback::LED_RGB],
+                p[Ds5Feedback::LED_RGB + 1],
+                p[Ds5Feedback::LED_RGB + 2]
+            ),
+            (0x11, 0x22, 0x33)
+        );
+        // Everything else stays zero — an over-broad packet would blank the triggers/player LEDs
+        // it never meant to touch.
+        let touched = [
+            1,
+            Ds5Feedback::LED_RGB,
+            Ds5Feedback::LED_RGB + 1,
+            Ds5Feedback::LED_RGB + 2,
+        ];
+        assert!(p
+            .iter()
+            .enumerate()
+            .all(|(i, &b)| touched.contains(&i) || b == 0));
+    }
+
+    #[test]
+    fn player_leds_are_masked_to_five_bits() {
+        let p = Ds5Feedback::player_packet(0xFF);
+        assert_eq!(p[1], 0x10, "valid_flag1 player-indicator bit");
+        assert_eq!(
+            p[Ds5Feedback::PAD_LIGHTS],
+            0x1F,
+            "high bits are not ours to set"
+        );
+        let p = Ds5Feedback::player_packet(0b0000_0101);
+        assert_eq!(p[Ds5Feedback::PAD_LIGHTS], 0b0000_0101);
+    }
+
+    /// which 1 = R2 and which 0 = L2 — and the RIGHT block sits FIRST in the report, which is the
+    /// pairing most likely to be transcribed backwards.
+    #[test]
+    fn trigger_which_selects_the_right_flag_and_offset() {
+        let eff: Vec<u8> = (1..=11).collect();
+
+        let r = Ds5Feedback::trigger_packet(1, &eff);
+        assert_eq!(r[0], 0x04, "valid_flag0 R2 bit");
+        assert_eq!(
+            &r[Ds5Feedback::RIGHT_TRIGGER..Ds5Feedback::RIGHT_TRIGGER + 11],
+            &eff[..]
+        );
+        assert_eq!(
+            r[Ds5Feedback::LEFT_TRIGGER],
+            0,
+            "the other trigger is untouched"
+        );
+
+        let l = Ds5Feedback::trigger_packet(0, &eff);
+        assert_eq!(l[0], 0x08, "valid_flag0 L2 bit");
+        assert_eq!(
+            &l[Ds5Feedback::LEFT_TRIGGER..Ds5Feedback::LEFT_TRIGGER + 11],
+            &eff[..]
+        );
+        assert_eq!(l[Ds5Feedback::RIGHT_TRIGGER], 0);
+    }
+
+    #[test]
+    fn an_oversized_effect_is_clamped_rather_than_overflowing_into_the_next_field() {
+        let long = vec![0xAAu8; 40];
+        let p = Ds5Feedback::trigger_packet(1, &long);
+        assert_eq!(p.len(), 47);
+        // Exactly TRIGGER_LEN bytes written; the left block must not be scribbled on.
+        assert_eq!(p[Ds5Feedback::RIGHT_TRIGGER + 10], 0xAA);
+        assert_eq!(p[Ds5Feedback::RIGHT_TRIGGER + 11], 0);
+        assert_eq!(p[Ds5Feedback::LEFT_TRIGGER], 0);
+    }
+
+    #[test]
+    fn a_short_effect_leaves_the_rest_of_the_block_zeroed() {
+        let p = Ds5Feedback::trigger_packet(0, &[0x02, 0x99]);
+        assert_eq!(p[Ds5Feedback::LEFT_TRIGGER], 0x02);
+        assert_eq!(p[Ds5Feedback::LEFT_TRIGGER + 1], 0x99);
+        assert!(
+            p[Ds5Feedback::LEFT_TRIGGER + 2..Ds5Feedback::LEFT_TRIGGER + 11]
+                .iter()
+                .all(|&b| b == 0)
+        );
+    }
+
+    /// An empty effect is a well-formed all-zero block: mode 0x00 = release. It must still assert
+    /// its enable bit, or the pad keeps whatever effect it was holding.
+    #[test]
+    fn an_empty_effect_is_a_release_not_a_no_op() {
+        let p = Ds5Feedback::trigger_packet(1, &[]);
+        assert_eq!(p[0], 0x04);
+        assert!(
+            p[Ds5Feedback::RIGHT_TRIGGER..Ds5Feedback::RIGHT_TRIGGER + 11]
+                .iter()
+                .all(|&b| b == 0)
+        );
+    }
+}
+
+#[cfg(test)]
+mod reset_packet_tests {
+    use super::*;
+
+    /// The exact bytes a teardown sends to hand a DualSense back neutral. The *timing* of this
+    /// (slot close) needs a live SDL handle and stays untestable, so pin the payloads: a wrong
+    /// enable flag or a non-zero mode byte would silently leave the effect latched, which is the
+    /// bug this reset exists to prevent.
+    #[test]
+    fn reset_packets_release_the_triggers_and_darken_the_lights() {
+        // Trigger release: mode 0x00 with no parameters, on the side's own enable bit.
+        let l = Ds5Feedback::trigger_packet(0, &[0u8; 11]);
+        assert_eq!(l[0], 0x08, "left-trigger enable bit");
+        assert!(
+            l[Ds5Feedback::LEFT_TRIGGER..Ds5Feedback::LEFT_TRIGGER + 11]
+                .iter()
+                .all(|&b| b == 0),
+            "an all-zero block is mode 0x00 = no effect"
+        );
+        let r = Ds5Feedback::trigger_packet(1, &[0u8; 11]);
+        assert_eq!(r[0], 0x04, "right-trigger enable bit");
+        assert!(
+            r[Ds5Feedback::RIGHT_TRIGGER..Ds5Feedback::RIGHT_TRIGGER + 11]
+                .iter()
+                .all(|&b| b == 0)
+        );
+
+        // Lightbar off: enable bit set, RGB all zero. The enable bit matters — without it the pad
+        // ignores the payload and keeps the game's last colour.
+        let bar = Ds5Feedback::lightbar_packet(0, 0, 0);
+        assert_eq!(bar[1], 0x04, "lightbar enable bit");
+        assert_eq!(
+            &bar[Ds5Feedback::LED_RGB..Ds5Feedback::LED_RGB + 3],
+            &[0, 0, 0]
+        );
+
+        // Player indicator cleared.
+        let pl = Ds5Feedback::player_packet(0);
+        assert_eq!(pl[1], 0x10, "player-LED enable bit");
+        assert_eq!(pl[Ds5Feedback::PAD_LIGHTS], 0);
+    }
+}
+
+#[cfg(test)]
+mod player_led_tests {
+    use super::*;
+
+    /// Both conventions that reach this wire spell "player N" as N lit LEDs, so the count is the
+    /// player number regardless of WHICH bits a given pad lights. Pinned because the mapping is
+    /// otherwise only obvious once you have seen both patterns side by side.
+    #[test]
+    fn player_index_counts_lit_leds_for_both_conventions() {
+        // DualSense / hid-playstation patterns — non-contiguous, symmetric about the centre LED.
+        assert_eq!(player_index_from_bits(0x04), Some(0)); // player 1
+        assert_eq!(player_index_from_bits(0x0A), Some(1)); // player 2
+        assert_eq!(player_index_from_bits(0x15), Some(2)); // player 3
+        assert_eq!(player_index_from_bits(0x1B), Some(3)); // player 4
+        assert_eq!(player_index_from_bits(0x1F), Some(4)); // player 5
+
+        // Switch/XInput style — a contiguous run of low bits, the same count each time.
+        assert_eq!(player_index_from_bits(0x01), Some(0));
+        assert_eq!(player_index_from_bits(0x03), Some(1));
+        assert_eq!(player_index_from_bits(0x07), Some(2));
+        assert_eq!(player_index_from_bits(0x0F), Some(3));
+    }
+
+    /// No lit LED is "no player", NOT player 0 — the difference between LEDs off and player 1 lit.
+    #[test]
+    fn no_lit_led_is_no_player() {
+        assert_eq!(player_index_from_bits(0x00), None);
+        // Only the low 5 bits are player LEDs; junk above them must not invent a player.
+        assert_eq!(player_index_from_bits(0xE0), None);
+    }
+
+    /// The mask is applied before counting, so out-of-range bits cannot inflate the index past
+    /// the 5 real LEDs.
+    #[test]
+    fn high_bits_are_masked_off_before_counting() {
+        assert_eq!(player_index_from_bits(0xFF), Some(4)); // 0x1F worth of LEDs, not 8
+        assert_eq!(player_index_from_bits(0xE4), Some(0)); // 0x04 with junk on top
     }
 }

crates/pf-client-core/src/lib.rs

@@ -47,6 +47,11 @@ pub mod os;
 // Client settings profiles: the override catalog + the one connect-time resolver
 // (design/client-settings-profiles.md §4). Sits beside `trust`, which owns the host records
 // the bindings live on.
+// Pad audio (the 0xD1 plane): DualSense voice-coil haptics + speaker rendered on the wired
+// physical pad's own 4-ch audio device — correlation, the per-session renderer worker, and
+// the tier-A pad registry the gamepad worker feeds it through.
+#[cfg(any(target_os = "linux", windows))]
+pub mod pad_audio;
 #[cfg(any(target_os = "linux", windows))]
 pub mod profiles;
 #[cfg(any(target_os = "linux", windows))]

crates/pf-client-core/src/session.rs

@@ -44,6 +44,14 @@ pub struct SessionParams {
     /// Run the uplink through the platform's echo cancellation ([`Settings::echo_cancel`]).
     /// Ignored when `mic_enabled` is false; `PUNKTFUNK_NO_AEC=1` overrides it off.
     pub echo_cancel: bool,
+    /// Render the host's per-pad DualSense voice-coil haptics stream (0xD1 kind 0) on a wired
+    /// physical DualSense ([`crate::trust::Settings::pad_haptics`]). With `pad_speaker` it
+    /// gates the `CLIENT_CAP_PAD_AUDIO` advertisement and the pad-audio renderer thread.
+    pub pad_haptics: bool,
+    /// Where the DualSense built-in-speaker stream (0xD1 kind 1) goes: `"pad"` | `"mix"` |
+    /// `"off"` ([`crate::trust::Settings::pad_speaker`]; `"mix"` is a TODO that renders as
+    /// off — see [`crate::pad_audio::speaker_active`]).
+    pub pad_speaker: String,
     /// Share the clipboard with this host (the per-host `KnownHost::clipboard_sync`). The
     /// bridge additionally needs the host to advertise `HOST_CAP_CLIPBOARD`.
     pub clipboard: bool,
@@ -356,6 +364,11 @@ fn pump(
             );
         }
     }
+    // Pad audio (0xD1): advertise only when the settings could render a stream — the per-pad
+    // tier-A detection at slot open (gamepad.rs) still decides which pads declare render caps
+    // on their arrivals, so this bit alone changes nothing without a wired DualSense.
+    let pad_speaker_on = crate::pad_audio::speaker_active(&params.pad_speaker);
+    let pad_audio_on = params.pad_haptics || pad_speaker_on;
     let connector = match NativeClient::connect(
         &params.host,
         params.port,
@@ -379,6 +392,11 @@ fn pump(
             0
         }) | (if params.phase_lock {
             punktfunk_core::quic::CLIENT_CAP_PHASE_LOCK
+        } else {
+            0
+            // PAD_AUDIO: the embedder can render per-pad DualSense haptics/speaker (see above).
+        }) | (if pad_audio_on {
+            punktfunk_core::quic::CLIENT_CAP_PAD_AUDIO
         } else {
             0
         }),
@@ -501,6 +519,20 @@ fn pump(
     // app-lifetime service's job (the UI attaches it on Connected). Audio runs on its own
     // thread (one puller per plane), blocking on the audio queue like the Apple client.
     let audio_thread = spawn_audio(connector.clone(), stop.clone());
+    // Pad audio (0xD1): its own drain thread (that plane's single consumer), spawned whenever
+    // the settings could render. The output device is opened LAZILY once frames actually
+    // arrive — which only happens after a tier-A pad declared render caps on its arrival — so
+    // a session without a wired DualSense costs one idle 10 ms poll loop.
+    let pad_audio_thread = pad_audio_on
+        .then(|| {
+            crate::pad_audio::spawn(
+                connector.clone(),
+                stop.clone(),
+                params.pad_haptics,
+                pad_speaker_on,
+            )
+        })
+        .flatten();
     // The shared clipboard (design/clipboard-and-file-transfer.md §5): its own thread, since
     // `next_clip` blocks and the OS clipboard calls can wait on other apps. Returns straight
     // away when the host has no clipboard capability, so spawning is unconditional.
@@ -1066,6 +1098,9 @@ fn pump(
     if let Some(t) = audio_thread {
         let _ = t.join(); // exits within its 100 ms pull timeout once `stop` is set
     }
+    if let Some(t) = pad_audio_thread {
+        let _ = t.join(); // exits within its 10 ms pull timeout once `stop` is set
+    }
     if let Some(t) = clipboard_thread {
         let _ = t.join(); // exits within its next_clip wait once `stop` is set
     }

crates/pf-client-core/src/trust.rs

@@ -1024,6 +1024,21 @@ pub struct Settings {
     /// `PUNKTFUNK_AUDIO_SOURCE`).
     #[serde(default)]
     pub mic_device: String,
+    /// Render the host's per-pad DualSense voice-coil haptics stream (the 0xD1 plane, kind 0)
+    /// on a WIRED physical DualSense's own audio device (tier A — Bluetooth pads expose no
+    /// audio device). Gates the `CLIENT_CAP_PAD_AUDIO` advertisement and the per-pad arrival
+    /// capability bit; wire rumble is suppressed for a pad whose haptics stream is live (the
+    /// stream carries the feedback — see `gamepad.rs`, the SDL disable-bit trap). Default ON:
+    /// the capable-and-agreed negotiation means it changes nothing without a capable host AND
+    /// a wired DS5. `default` so pre-existing stores load with it on.
+    #[serde(default = "default_true")]
+    pub pad_haptics: bool,
+    /// Where the DualSense built-in-speaker stream (0xD1 kind 1) is rendered: `"pad"` (default
+    /// — the physical pad's own speaker), `"mix"` (fold it into the main stream audio — a
+    /// declared TODO that renders as `"off"` today; see `pad_audio::speaker_active`), or
+    /// `"off"`. `default` so pre-existing stores load as `"pad"`.
+    #[serde(default = "default_pad_speaker")]
+    pub pad_speaker: String,
     /// Match-window resolution policy (design/midstream-resolution-resize.md D1): the
     /// stream mode follows the session window — the connect asks for the window's pixel
     /// size and a mid-session resize renegotiates the host's virtual display + encoder
@@ -1071,6 +1086,10 @@ fn default_true() -> bool {
     true
 }
 
+fn default_pad_speaker() -> String {
+    "pad".into()
+}
+
 impl Settings {
     /// The stats-overlay tier, resolving pre-tier stores: an old `show_stats = false`
     /// reads as Off, everything else as Normal (≈ what the pre-tier overlay showed).
@@ -1179,6 +1198,8 @@ impl Default for Settings {
             invert_scroll: false,
             speaker_device: String::new(),
             mic_device: String::new(),
+            pad_haptics: true,
+            pad_speaker: "pad".into(),
             match_window: false,
             last_window_w: 0,
             last_window_h: 0,

crates/pf-clipboard/src/host.rs

@@ -309,6 +309,24 @@ pub fn offer_wire_mimes(raw: &[String]) -> Vec<&'static str> {
     out
 }
 
+/// Whether a non-canonical, client-supplied MIME is safe to hand to Wayland as a string argument.
+///
+/// Deliberately strict: printable ASCII only (so no NUL and no other control byte can reach the
+/// `CString` in the generated encoder), bounded length, and it must actually look like a MIME type.
+/// A real `type/subtype[;params]` passes; nothing that could crash or confuse the compositor does.
+#[cfg(target_os = "linux")]
+fn valid_passthrough_mime(m: &str) -> bool {
+    let Some((ty, rest)) = m.split_once('/') else {
+        return false;
+    };
+    !ty.is_empty()
+        && !rest.is_empty()
+        && m.len() <= 255
+        // 0x21..=0x7E: printable ASCII without space. Excludes NUL, every other control byte, and
+        // any non-ASCII byte.
+        && m.bytes().all(|b| (0x21..=0x7E).contains(&b))
+}
+
 /// The Wayland MIMEs to advertise when installing a source for a client's offer. Each wire MIME
 /// expands to its canonical Wayland name(s); a rich-text-only offer also advertises `text/plain`
 /// so plain-text targets always paste (§3.5 synthesis — destination-side, one direction only).
@@ -342,7 +360,17 @@ pub fn wayland_offers_for(wire_mimes: &[String]) -> Vec<String> {
             WIRE_PNG => push("image/png"),
             WIRE_JPEG => push("image/jpeg"),
             WIRE_GIF => push("image/gif"),
-            other => push(other),
+            // A MIME we don't canonicalize is passed through verbatim — so it is the one value on
+            // this path the CLIENT fully controls, and it ends up as a Wayland string argument.
+            // The wayland-scanner-generated request encoder builds a `CString` and `unwrap()`s it,
+            // so a single interior NUL turns one control message into a host clipboard panic
+            // (2026-08-05 review L-8). `String::from_utf8_lossy` on the wire preserves `\0`, so
+            // nothing upstream removes it. Validate here, at the boundary where the value stops
+            // being ours and becomes libwayland's.
+            other if valid_passthrough_mime(other) => push(other),
+            other => {
+                tracing::debug!(mime = %other.escape_debug(), "clipboard: dropping a malformed client MIME");
+            }
         }
     }
     // Synthesis: rich text without plain text → also advertise plain (the source derives it lazily).
@@ -389,6 +417,38 @@ mod tests {
         assert_eq!(offer_wire_mimes(&raw), vec![WIRE_TEXT, WIRE_HTML]);
     }
 
+    /// One control message must not be able to panic the host clipboard coordinator
+    /// (2026-08-05 review L-8). The passthrough branch is the only place a client string becomes a
+    /// Wayland argument, and the generated encoder `unwrap()`s a `CString` built from it.
+    #[test]
+    fn passthrough_mimes_cannot_carry_a_nul_or_control_byte() {
+        // The crash payload: an interior NUL survives `String::from_utf8_lossy` on the wire.
+        assert!(!valid_passthrough_mime("image/webp\0"));
+        assert!(!valid_passthrough_mime("\0"));
+        assert!(!valid_passthrough_mime("image/\0webp"));
+        // Other control bytes and whitespace are refused for the same reason.
+        assert!(!valid_passthrough_mime("image/web\np"));
+        assert!(!valid_passthrough_mime("image/web p"));
+        assert!(!valid_passthrough_mime("image/web\tp"));
+        // Shapes that are not a MIME type at all.
+        assert!(!valid_passthrough_mime(""));
+        assert!(!valid_passthrough_mime("noslash"));
+        assert!(!valid_passthrough_mime("/nosubtype"));
+        assert!(!valid_passthrough_mime("notype/"));
+        assert!(!valid_passthrough_mime(&format!(
+            "image/{}",
+            "x".repeat(300)
+        )));
+        // Legitimate uncanonicalized MIMEs still pass through.
+        assert!(valid_passthrough_mime("image/webp"));
+        assert!(valid_passthrough_mime("application/x-custom+json"));
+        assert!(valid_passthrough_mime("text/plain;charset=utf-8"));
+
+        // End to end: the offer list is built without the malformed entry, and does not panic.
+        let offers = wayland_offers_for(&["image/webp\0".to_string(), WIRE_PNG.to_string()]);
+        assert_eq!(offers, vec!["image/png".to_string()]);
+    }
+
     #[test]
     fn pick_wayland_mime_prefers_canonical() {
         let avail = vec!["text/plain".to_string(), "UTF8_STRING".to_string()];

crates/pf-clipboard/src/host/winfmt.rs

@@ -169,7 +169,27 @@ fn strip_trailing_nul(b: &[u8]) -> &[u8] {
 /// bytes (BITMAPINFOHEADER, 32bpp BGRA, BI_RGB, bottom-up). GIFs contribute their first frame.
 /// `None` when the bytes don't decode — the caller leaves the format unrendered (empty paste).
 pub fn image_to_dib(bytes: &[u8]) -> Option<Vec<u8>> {
-    let img = image::load_from_memory(bytes).ok()?;
+    // Bound the DECODE, not just the result.
+    //
+    // These bytes are client-supplied, and `load_from_memory` used the `image` crate's DEFAULT
+    // limits — 512 MiB of decode allowance — while the 32767 dimension check below only ran on the
+    // already-decoded image. So a small, valid PNG declaring enormous dimensions was allocated in
+    // full before anything rejected it: ~1000× amplification from a few KB of wire (2026-08-05
+    // review L-9). Limits applied here make the allocation refuse instead.
+    //
+    // The caps are the clipboard's own contract expressed up front: the same 32767 per side that
+    // is checked below (a CF_DIB cannot express more), and 256 MiB, which is more than the largest
+    // representable 32bpp image anyone pastes and far less than a memory-exhaustion primitive.
+    let mut limits = image::Limits::default();
+    limits.max_image_width = Some(32767);
+    limits.max_image_height = Some(32767);
+    limits.max_alloc = Some(256 * 1024 * 1024);
+    let reader = image::ImageReader::new(std::io::Cursor::new(bytes))
+        .with_guessed_format()
+        .ok()?;
+    let mut reader = reader;
+    reader.limits(limits);
+    let img = reader.decode().ok()?;
     let rgba = img.to_rgba8();
     let (w, h) = (rgba.width() as usize, rgba.height() as usize);
     if w == 0 || h == 0 || w > 32767 || h > 32767 {

crates/pf-inject/src/inject/hidout_dedup.rs

@@ -5,19 +5,42 @@
 //! rich state every report; this forwards only genuine changes (one-shot pulses always fire).
 
 use punktfunk_core::quic::HidOutput;
+use std::time::{Duration, Instant};
+
+/// How often the latched rich state is re-emitted even though nothing changed.
+///
+/// The 0xCD plane is deduped AND rides unreliable datagrams, which is a bad pairing: a change is
+/// forwarded exactly once, so if that datagram is dropped the game will never produce it again —
+/// it keeps re-sending the same value and the dedup swallows every copy. The pad is then left
+/// holding the PREVIOUS value: the last weapon's trigger effect, the last lightbar colour, for as
+/// long as the game keeps that setting. For a trigger effect that can be the rest of a level.
+///
+/// Slow on purpose. This is a repair mechanism, not a transport — at one second a lost update
+/// costs a noticeable but bounded wrong-feel window, while the steady-state cost is at most four
+/// small datagrams per second per pad, against a rumble plane that already resends at ~120 ms.
+const RENEW_EVERY: Duration = Duration::from_millis(1000);
 
 /// Per-pad dedup for the DualSense HID-output feedback plane (0xCD). A game's DualSense output report
 /// bundles rumble + lightbar + player-LEDs + adaptive-triggers into one report, so a pad that is
 /// merely *rumbling* re-sends its (unchanged) lightbar / LED / trigger state on every output report.
 /// The managers already dedup rumble; this does the same for the rich [`HidOutput`] feedback so the
-/// 0xCD plane carries only genuine changes. State (`Led` / `PlayerLeds` / `Trigger`) is deduped by
-/// value; a one-shot `TrackpadHaptic` pulse is always forwarded (each pulse must fire).
+/// 0xCD plane carries only genuine changes. State (`Led` / `PlayerLeds` / `Trigger` / `AudioCtl`)
+/// is deduped by value; a one-shot `TrackpadHaptic` pulse is always forwarded (each pulse must
+/// fire).
 #[derive(Clone, Default)]
 pub struct HidoutDedup {
     led: Option<(u8, u8, u8)>,
     player_leds: Option<u8>,
     /// Last-forwarded adaptive-trigger effect per side: `[0]` = L2, `[1]` = R2.
     trigger: [Option<Vec<u8>>; 2],
+    /// Last-forwarded audio-control state (`flags` + the raw volume/routing bytes).
+    audio_ctl: Option<(u8, [u8; 6])>,
+    /// Once-per-pad-lifetime field-diagnosis flag: set after the first forwarded `AudioCtl`
+    /// carrying the haptics-select bit was logged (cleared with the rest on (re)plug).
+    haptics_select_logged: bool,
+    /// When anything was last put on the wire for this pad. `None` = nothing latched yet, so
+    /// there is nothing to renew. See [`RENEW_EVERY`].
+    last_sent: Option<Instant>,
 }
 
 impl HidoutDedup {
@@ -29,7 +52,53 @@ impl HidoutDedup {
 
     /// Whether `h` should be forwarded: `true` for a genuine change (remembering the new value) or a
     /// one-shot pulse; `false` if it repeats the last-forwarded value for its kind.
-    pub fn should_forward(&mut self, h: &HidOutput) -> bool {
+    ///
+    /// `now` only stamps the renewal clock ([`Self::renewals`]) — forwarding a change resets it, so
+    /// a plane the game is actively changing never pays for a renewal it does not need.
+    pub fn should_forward(&mut self, h: &HidOutput, now: Instant) -> bool {
+        let fwd = self.decide(h);
+        if fwd {
+            self.last_sent = Some(now);
+        }
+        fwd
+    }
+
+    /// Re-emit the latched rich state, so one lost datagram cannot strand the pad on the previous
+    /// value. Returns the reports to send (empty until [`RENEW_EVERY`] has passed since anything
+    /// last went out); every one is idempotent, so a client that DID receive the original simply
+    /// re-applies it.
+    ///
+    /// One-shots are deliberately absent: replaying a `TrackpadHaptic` pulse would be a *new*
+    /// pulse, not a repair, and `HidRaw` is already re-sent verbatim by the device's own refresh
+    /// cadence (see the note in [`Self::decide`]).
+    pub fn renewals(&mut self, pad: u8, now: Instant) -> Vec<HidOutput> {
+        if self
+            .last_sent
+            .is_none_or(|t| now.duration_since(t) < RENEW_EVERY)
+        {
+            return Vec::new();
+        }
+        self.last_sent = Some(now);
+        let mut out = Vec::new();
+        if let Some((r, g, b)) = self.led {
+            out.push(HidOutput::Led { pad, r, g, b });
+        }
+        if let Some(bits) = self.player_leds {
+            out.push(HidOutput::PlayerLeds { pad, bits });
+        }
+        for (which, effect) in self.trigger.iter().enumerate() {
+            if let Some(effect) = effect {
+                out.push(HidOutput::Trigger {
+                    pad,
+                    which: which as u8,
+                    effect: effect.clone(),
+                });
+            }
+        }
+        out
+    }
+
+    fn decide(&mut self, h: &HidOutput) -> bool {
         match h {
             HidOutput::Led { r, g, b, .. } => {
                 let v = Some((*r, *g, *b));
@@ -60,6 +129,25 @@ impl HidoutDedup {
             }
             // One-shot haptic pulse (Steam voice-coil) — state-less, always fires.
             HidOutput::TrackpadHaptic { .. } => true,
+            HidOutput::AudioCtl { pad, flags, raw } => {
+                let v = Some((*flags, *raw));
+                if self.audio_ctl == v {
+                    false
+                } else {
+                    // Field-diagnosis signal, once per pad lifetime: a title driving the DS5's
+                    // audio haptics (not plain rumble emulation, whose all-zero audio region
+                    // never reaches here) — the trace that tells "the game does audio haptics"
+                    // apart from "the client just doesn't render them".
+                    if flags & 0x01 != 0 && !self.haptics_select_logged {
+                        self.haptics_select_logged = true;
+                        tracing::info!(
+                            "DS5 title asserted haptics-select (audio haptics) pad={pad}"
+                        );
+                    }
+                    self.audio_ctl = v;
+                    true
+                }
+            }
             // Raw as-is passthrough reports must NEVER dedup: the physical device's firmware
             // watchdogs RELY on identical periodic refreshes (Triton rumble re-sent every ~40 ms
             // against a ~50 ms safety timeout, lizard-off every ~3 s) — dropping a repeat would
@@ -77,6 +165,7 @@ mod tests {
     /// trigger sides independently, never dedups one-shot haptic pulses, and re-arms after `clear`.
     #[test]
     fn hidout_dedup_forwards_only_changes() {
+        let t = Instant::now();
         let mut d = HidoutDedup::default();
         let led = |r| HidOutput::Led {
             pad: 0,
@@ -85,15 +174,15 @@ mod tests {
             b: 0,
         };
         // First value forwards; an exact repeat is dropped; a change forwards again.
-        assert!(d.should_forward(&led(10)));
-        assert!(!d.should_forward(&led(10)));
-        assert!(d.should_forward(&led(20)));
+        assert!(d.should_forward(&led(10), t));
+        assert!(!d.should_forward(&led(10), t));
+        assert!(d.should_forward(&led(20), t));
 
         // Player LEDs dedup on their own field, independent of the lightbar.
         let pl = |bits| HidOutput::PlayerLeds { pad: 0, bits };
-        assert!(d.should_forward(&pl(0b101)));
-        assert!(!d.should_forward(&pl(0b101)));
-        assert!(!d.should_forward(&led(20))); // lightbar still unchanged
+        assert!(d.should_forward(&pl(0b101), t));
+        assert!(!d.should_forward(&pl(0b101), t));
+        assert!(!d.should_forward(&led(20), t)); // lightbar still unchanged
 
         // The two adaptive triggers (L2=0, R2=1) are tracked separately.
         let trig = |which, byte| HidOutput::Trigger {
@@ -101,10 +190,10 @@ mod tests {
             which,
             effect: vec![byte, 0, 0],
         };
-        assert!(d.should_forward(&trig(0, 1)));
-        assert!(d.should_forward(&trig(1, 1))); // same bytes, other side → still forwards
-        assert!(!d.should_forward(&trig(0, 1)));
-        assert!(d.should_forward(&trig(0, 2))); // L2 effect changed
+        assert!(d.should_forward(&trig(0, 1), t));
+        assert!(d.should_forward(&trig(1, 1), t)); // same bytes, other side → still forwards
+        assert!(!d.should_forward(&trig(0, 1), t));
+        assert!(d.should_forward(&trig(0, 2), t)); // L2 effect changed
 
         // One-shot haptic pulses are never deduped.
         let haptic = HidOutput::TrackpadHaptic {
@@ -114,13 +203,153 @@ mod tests {
             period: 2,
             count: 3,
         };
-        assert!(d.should_forward(&haptic));
-        assert!(d.should_forward(&haptic));
+        assert!(d.should_forward(&haptic, t));
+        assert!(d.should_forward(&haptic, t));
 
         // `clear` re-arms every kind.
         d.clear();
-        assert!(d.should_forward(&led(20)));
-        assert!(d.should_forward(&pl(0b101)));
-        assert!(d.should_forward(&trig(0, 2)));
+        assert!(d.should_forward(&led(20), t));
+        assert!(d.should_forward(&pl(0b101), t));
+        assert!(d.should_forward(&trig(0, 2), t));
+    }
+
+    /// A change is forwarded once and then deduped — so if that one datagram is lost, nothing else
+    /// would ever carry it. The renewal is what repairs that.
+    #[test]
+    fn latched_state_is_renewed_so_a_lost_datagram_is_not_permanent() {
+        let t = Instant::now();
+        let mut d = HidoutDedup::default();
+        let trig = HidOutput::Trigger {
+            pad: 3,
+            which: 1,
+            effect: vec![0x02, 0x90, 0xA0],
+        };
+        assert!(d.should_forward(&trig, t));
+        assert!(
+            !d.should_forward(&trig, t),
+            "the game re-sends it; the dedup swallows it"
+        );
+
+        // Nothing due yet.
+        assert!(d.renewals(3, t + Duration::from_millis(999)).is_empty());
+
+        // Past the window: the latched state goes out again, addressed to the right pad.
+        let out = d.renewals(3, t + Duration::from_millis(1000));
+        assert_eq!(out.len(), 1);
+        assert!(matches!(
+            &out[0],
+            HidOutput::Trigger { pad: 3, which: 1, effect } if effect == &vec![0x02, 0x90, 0xA0]
+        ));
+
+        // And it keeps repairing on the same cadence, not just once.
+        assert!(d.renewals(3, t + Duration::from_millis(1500)).is_empty());
+        assert_eq!(d.renewals(3, t + Duration::from_millis(2000)).len(), 1);
+    }
+
+    /// Every latched plane is renewed together, and a plane the game is actively driving does not
+    /// pay for renewals it does not need (a forward resets the clock).
+    #[test]
+    fn renewal_covers_every_latched_plane_and_an_active_plane_defers_it() {
+        let t = Instant::now();
+        let mut d = HidoutDedup::default();
+        assert!(d.should_forward(
+            &HidOutput::Led {
+                pad: 0,
+                r: 9,
+                g: 8,
+                b: 7
+            },
+            t
+        ));
+        assert!(d.should_forward(
+            &HidOutput::PlayerLeds {
+                pad: 0,
+                bits: 0b100
+            },
+            t
+        ));
+        assert!(d.should_forward(
+            &HidOutput::Trigger {
+                pad: 0,
+                which: 0,
+                effect: vec![1]
+            },
+            t
+        ));
+        assert!(d.should_forward(
+            &HidOutput::Trigger {
+                pad: 0,
+                which: 1,
+                effect: vec![2]
+            },
+            t
+        ));
+
+        let out = d.renewals(0, t + Duration::from_millis(1000));
+        assert_eq!(
+            out.len(),
+            4,
+            "lightbar + player LEDs + both triggers, got {out:?}"
+        );
+
+        // A genuine change re-stamps the clock, so the next renewal is a full window away.
+        let later = t + Duration::from_millis(1500);
+        assert!(d.should_forward(
+            &HidOutput::Led {
+                pad: 0,
+                r: 1,
+                g: 2,
+                b: 3
+            },
+            later
+        ));
+        assert!(d.renewals(0, later + Duration::from_millis(999)).is_empty());
+        assert!(!d
+            .renewals(0, later + Duration::from_millis(1000))
+            .is_empty());
+    }
+
+    /// Nothing latched = nothing to renew; a one-shot pulse must never be replayed as a "repair".
+    #[test]
+    fn renewal_is_silent_with_nothing_latched_and_never_replays_a_pulse() {
+        let t = Instant::now();
+        let mut d = HidoutDedup::default();
+        assert!(d.renewals(0, t + Duration::from_secs(60)).is_empty());
+
+        let pulse = HidOutput::TrackpadHaptic {
+            pad: 0,
+            side: 0,
+            amplitude: 1,
+            period: 2,
+            count: 3,
+        };
+        assert!(d.should_forward(&pulse, t));
+        // The pulse stamped the clock but latched no state, so the renewal has nothing to repeat.
+        assert!(d.renewals(0, t + Duration::from_millis(1000)).is_empty());
+    }
+
+    /// `AudioCtl` dedups by value like the other state kinds: an identical repeat (every output
+    /// report re-sends the unchanged audio region) is dropped, a flags-only or raw-only change
+    /// forwards again, and `clear` re-arms — including the once-per-pad haptics-select log flag.
+    #[test]
+    fn audio_ctl_dedups_by_value() {
+        let mut d = HidoutDedup::default();
+        let t = Instant::now();
+        let audio = |flags, vol| HidOutput::AudioCtl {
+            pad: 0,
+            flags,
+            raw: [vol, 0, 0, 0, 0, 0],
+        };
+        // Identical twice → exactly one emission.
+        assert!(d.should_forward(&audio(0x17, 0x50), t));
+        assert!(!d.should_forward(&audio(0x17, 0x50), t));
+        // Either half changing (flags, or the raw region) forwards again.
+        assert!(d.should_forward(&audio(0x16, 0x50), t));
+        assert!(d.should_forward(&audio(0x16, 0x60), t));
+        // The other kinds' state is untouched by audio traffic.
+        assert!(d.should_forward(&HidOutput::PlayerLeds { pad: 0, bits: 1 }, t));
+        // `clear` (pad re-plug) re-arms the value dedup.
+        d.clear();
+        assert!(d.should_forward(&audio(0x16, 0x60), t));
     }
 }

crates/pf-inject/src/inject/linux/dualsense.rs

@@ -17,6 +17,11 @@ use super::dualsense_proto::{
     DS_EDGE_PRODUCT, DS_FEATURE_CALIBRATION, DS_FEATURE_FIRMWARE, DS_INPUT_REPORT_LEN, DS_PRODUCT,
     DS_TOUCH_H, DS_TOUCH_W, DS_VENDOR, DUALSENSE_EDGE_RDESC, DUALSENSE_RDESC,
 };
+use crate::uhid_abi::{
+    put_cstr, BUS_USB, HID_MAX_DESCRIPTOR_SIZE, UHID_CREATE2, UHID_DESTROY, UHID_EVENT_SIZE,
+    UHID_GET_REPORT, UHID_GET_REPORT_REPLY, UHID_INPUT2, UHID_OUTPUT, UHID_PATH, UHID_SET_REPORT,
+    UHID_SET_REPORT_REPLY,
+};
 use crate::uhid_manager::{PadFeedback, PadProto, UhidManager};
 use anyhow::{Context, Result};
 use punktfunk_core::quic::RichInput;
@@ -24,27 +29,6 @@ use std::fs::{File, OpenOptions};
 use std::io::{Read, Write};
 use std::os::unix::fs::OpenOptionsExt;
 
-// /dev/uhid event ABI (linux/uhid.h). `struct uhid_event` is __packed__: a u32 `type` then a
-// union whose largest member is uhid_create2_req (128+64+64 + 2+2 + 4*4 + rd_data[4096] = 4372).
-const UHID_PATH: &str = "/dev/uhid";
-const UHID_DESTROY: u32 = 1;
-const UHID_OUTPUT: u32 = 6;
-const UHID_GET_REPORT: u32 = 9;
-const UHID_GET_REPORT_REPLY: u32 = 10;
-const UHID_CREATE2: u32 = 11;
-const UHID_INPUT2: u32 = 12;
-const UHID_SET_REPORT: u32 = 13;
-const UHID_SET_REPORT_REPLY: u32 = 14;
-const HID_MAX_DESCRIPTOR_SIZE: usize = 4096;
-const UHID_EVENT_SIZE: usize = 4 + 4372; // type + union (create2)
-const BUS_USB: u16 = 0x03;
-
-/// Copy a NUL-padded C string field into the event buffer.
-fn put_cstr(ev: &mut [u8], off: usize, cap: usize, s: &str) {
-    let n = s.len().min(cap - 1);
-    ev[off..off + n].copy_from_slice(&s.as_bytes()[..n]); // rest already zero (NUL-terminated)
-}
-
 /// The UHID identity a [`DualSensePad`] is created with — the plain DualSense or the Edge (same
 /// driver, same report codec; the Edge differs by PID + descriptor and carries the four extra
 /// `buttons[2]` bits). Mirrors the uinput pad's `PadIdentity` shape.

crates/pf-inject/src/inject/linux/dualshock4.rs

@@ -18,6 +18,11 @@ use super::dualshock4_proto::{
     parse_ds4_output, serialize_state, Ds4Feedback, DS4_INPUT_REPORT_LEN, DS4_PRODUCT, DS4_TOUCH_H,
     DS4_TOUCH_W, DS4_VENDOR,
 };
+use crate::uhid_abi::{
+    put_cstr, BUS_USB, HID_MAX_DESCRIPTOR_SIZE, UHID_CREATE2, UHID_DESTROY, UHID_EVENT_SIZE,
+    UHID_GET_REPORT, UHID_GET_REPORT_REPLY, UHID_INPUT2, UHID_OUTPUT, UHID_PATH, UHID_SET_REPORT,
+    UHID_SET_REPORT_REPLY,
+};
 use crate::uhid_manager::{PadFeedback, PadProto, UhidManager};
 use anyhow::{Context, Result};
 use punktfunk_core::quic::{HidOutput, RichInput};
@@ -25,20 +30,6 @@ use std::fs::{File, OpenOptions};
 use std::io::{Read, Write};
 use std::os::unix::fs::OpenOptionsExt;
 
-// /dev/uhid event ABI (linux/uhid.h) — identical to the DualSense backend's; see `super::dualsense`.
-const UHID_PATH: &str = "/dev/uhid";
-const UHID_DESTROY: u32 = 1;
-const UHID_OUTPUT: u32 = 6;
-const UHID_GET_REPORT: u32 = 9;
-const UHID_GET_REPORT_REPLY: u32 = 10;
-const UHID_CREATE2: u32 = 11;
-const UHID_INPUT2: u32 = 12;
-const UHID_SET_REPORT: u32 = 13;
-const UHID_SET_REPORT_REPLY: u32 = 14;
-const HID_MAX_DESCRIPTOR_SIZE: usize = 4096;
-const UHID_EVENT_SIZE: usize = 4 + 4372; // type + union (create2)
-const BUS_USB: u16 = 0x03;
-
 // Feature reports `hid-playstation` GET_REPORTs during DS4 init. The PAIRING report (0x12) is
 // MANDATORY — without a valid reply `dualshock4_create()` aborts and creates NO input devices; the
 // kernel reads the 6-byte device MAC from bytes 1..7. CALIBRATION (0x02) and FIRMWARE (0xa3) are
@@ -144,12 +135,6 @@ const DS4_RDESC: &[u8] = &[
     0xB1, 0x02, 0xC0,
 ];
 
-/// Copy a NUL-padded C string field into the event buffer.
-fn put_cstr(ev: &mut [u8], off: usize, cap: usize, s: &str) {
-    let n = s.len().min(cap - 1);
-    ev[off..off + n].copy_from_slice(&s.as_bytes()[..n]); // rest already zero (NUL-terminated)
-}
-
 /// A virtual DualShock 4 backed by `/dev/uhid` (hand-rolled codec mirroring the DualSense pad's).
 /// Dropping it destroys the device (the kernel tears down the bound `hid-playstation` interface).
 pub struct DualShock4Pad {

crates/pf-inject/src/inject/linux/gamepad.rs

@@ -254,13 +254,45 @@ fn ioctl_ptr<T>(fd: i32, req: libc::c_ulong, arg: *mut T, what: &str) -> Result<
     Ok(())
 }
 
+/// The window a played effect occupies: `replay.delay` of silence, then `replay.length` of rumble.
+#[derive(Clone, Copy)]
+struct Playback {
+    /// When the effect starts contributing — `play + replay.delay`. Until then it is armed but
+    /// silent, which is the whole point of the delay.
+    starts: Instant,
+    /// When it stops, or `None` for replay length 0 (until explicitly stopped).
+    ends: Option<Instant>,
+}
+
 /// One FF effect a game uploaded: rumble magnitudes + playback state.
 struct Effect {
     strong: u16,
     weak: u16,
-    /// `Some(deadline)` while playing (replay length 0 = until stopped).
-    playing: Option<Option<Instant>>,
+    /// `Some(window)` while playing.
+    playing: Option<Playback>,
     replay_ms: u16,
+    /// `replay.delay` — how long after the play command the effect stays silent. Decoded from the
+    /// upload since forever and, until now, never acted on: the effect started immediately and
+    /// ended `replay.length` later, so anything scheduling a delayed effect (DirectInput under
+    /// Wine does this routinely) fired early AND finished early by the same amount.
+    delay_ms: u16,
+}
+
+impl Effect {
+    /// The window a play command at `at` opens: silent for `replay.delay`, then `replay.length` of
+    /// rumble (or until stopped, when the length is 0).
+    ///
+    /// `replay.length` is measured from the END of the delay, not from the play command, so the
+    /// delay shifts the whole window instead of eating into it. Split out from the `EV_FF` handler
+    /// purely so this is testable — the handler itself needs a live uinput fd.
+    fn window(&self, at: Instant) -> Playback {
+        let starts = at + Duration::from_millis(self.delay_ms as u64);
+        Playback {
+            starts,
+            ends: (self.replay_ms > 0)
+                .then(|| starts + Duration::from_millis(self.replay_ms as u64)),
+        }
+    }
 }
 
 /// The force-feedback half of a virtual pad — the game-side effect table plus the mixdown policy
@@ -268,7 +300,6 @@ struct Effect {
 /// the policy is pure and unit-testable without a live uinput fd.
 struct FfState {
     effects: HashMap<i16, Effect>,
-    next_effect_id: i16,
     gain: u32,
     /// Last `(low, high)` reported, to dedup.
     last_mix: (u16, u16),
@@ -284,7 +315,6 @@ impl FfState {
     fn new() -> FfState {
         FfState {
             effects: HashMap::new(),
-            next_effect_id: 0,
             gain: 0xFFFF,
             last_mix: (0, 0),
             last_activity: Instant::now(),
@@ -299,17 +329,29 @@ impl FfState {
     /// Mix: sum playing effects (expiring finished ones, force-stopping abandoned infinite ones),
     /// scale by gain. Returns the new `(low, high)` only when it changed since the last call.
     fn mix(&mut self, now: Instant, idle: Option<Duration>) -> Option<(u16, u16)> {
-        let stale = idle.is_some_and(|t| now.duration_since(self.last_activity) >= t);
+        let quiet_since = |t: Instant| idle.is_some_and(|d| now.duration_since(t) >= d);
+        let plane_stale = quiet_since(self.last_activity);
         let (mut strong, mut weak) = (0u32, 0u32);
         for e in self.effects.values_mut() {
-            let Some(deadline) = e.playing else { continue };
-            match deadline {
+            let Some(p) = e.playing else { continue };
+            // Still inside `replay.delay`: armed, silent, and NOT a candidate for expiry or the
+            // abandoned-effect force-off — it has not had its turn yet.
+            if now < p.starts {
+                continue;
+            }
+            match p.ends {
                 Some(d) if now >= d => e.playing = None,
                 // An infinite-replay effect the game stopped driving (no FF traffic for the whole
                 // idle window) — the alive-but-abandoned case the kernel's close-time auto-erase
                 // cannot see. Stop it once; a later EV_FF play re-arms it (and refreshes the
                 // clock). Mirrors the XUSB/UHID abandoned-rumble force-off.
-                None if stale => {
+                //
+                // "Abandoned" needs the effect to have been AUDIBLE for the window too, not just
+                // the plane quiet: the play command is itself the last activity, so an effect with
+                // a `replay.delay` longer than the window would otherwise be force-stopped the
+                // instant it finally started — silent the whole time it waited, then killed on its
+                // first contributing tick.
+                None if plane_stale && quiet_since(p.starts) => {
                     tracing::info!(
                         strong = e.strong,
                         weak = e.weak,
@@ -531,11 +573,13 @@ impl VirtualPad {
                     let mut up: UinputFfUpload = unsafe { std::mem::zeroed() };
                     up.request_id = ev.value as u32;
                     if ioctl_ptr(raw, UI_BEGIN_FF_UPLOAD, &mut up, "UI_BEGIN_FF_UPLOAD").is_ok() {
-                        let mut e = up.effect;
-                        if e.id == -1 {
-                            e.id = self.ff.next_effect_id;
-                            self.ff.next_effect_id = self.ff.next_effect_id.wrapping_add(1);
-                        }
+                        let e = up.effect;
+                        // No `id == -1` fallback: ff-core's `input_ff_upload` picks a free slot and
+                        // writes it into the effect BEFORE handing the request to uinput, so what
+                        // arrives here is always an assigned id. The fallback that used to allocate
+                        // one from a local counter could therefore never run, and a local counter is
+                        // the wrong answer anyway — the kernel owns that id space.
+                        debug_assert!(e.id >= 0, "uinput handed us an unassigned FF effect id");
                         if e.type_ == FF_RUMBLE {
                             let strong = u16::from_ne_bytes([e.u[0], e.u[1]]);
                             let weak = u16::from_ne_bytes([e.u[2], e.u[3]]);
@@ -544,10 +588,12 @@ impl VirtualPad {
                                 weak: 0,
                                 playing: None,
                                 replay_ms: 0,
+                                delay_ms: 0,
                             });
                             slot.strong = strong;
                             slot.weak = weak;
                             slot.replay_ms = e.replay_length;
+                            slot.delay_ms = e.replay_delay;
                         }
                         up.effect.id = e.id; // hand the assigned slot back to the kernel
                         up.retval = 0;
@@ -574,14 +620,7 @@ impl VirtualPad {
                 (EV_FF, code) => {
                     self.ff.note_activity();
                     if let Some(e) = self.ff.effects.get_mut(&(code as i16)) {
-                        e.playing = if ev.value != 0 {
-                            Some((e.replay_ms > 0).then(|| {
-                                Instant::now()
-                                    + std::time::Duration::from_millis(e.replay_ms as u64)
-                            }))
-                        } else {
-                            None
-                        };
+                        e.playing = (ev.value != 0).then(|| e.window(Instant::now()));
                     }
                 }
                 _ => {}
@@ -802,15 +841,34 @@ mod ff_state_tests {
         ff
     }
 
+    /// Playing from `at`, no delay, until explicitly stopped.
+    fn playing(at: Instant) -> Option<Playback> {
+        Some(Playback {
+            starts: at,
+            ends: None,
+        })
+    }
+
+    /// Playing from `at`, no delay, for `len`.
+    fn playing_for(at: Instant, len: Duration) -> Option<Playback> {
+        Some(Playback {
+            starts: at,
+            ends: Some(at + len),
+        })
+    }
+
     #[test]
     fn abandoned_infinite_effect_is_forced_off_after_idle_window() {
+        let now = Instant::now();
         let mut ff = ff_with(Effect {
             strong: 0x8000,
             weak: 0,
-            playing: Some(None),
+            // Playing since before the window: "abandoned" means audible AND unattended, so an
+            // effect that only just started is not a candidate however stale the plane is.
+            playing: playing(now - Duration::from_millis(2600)),
             replay_ms: 0,
+            delay_ms: 0,
         });
-        let now = Instant::now();
         assert_eq!(ff.mix(now, IDLE), Some((scaled(0x8000), 0)));
         assert_eq!(ff.mix(now, IDLE), None); // unchanged level dedups, still playing
                                              // The game goes silent on the FF plane past the idle window: cut, exactly once.
@@ -825,8 +883,9 @@ mod ff_state_tests {
         let mut ff = ff_with(Effect {
             strong: 0x4000,
             weak: 0,
-            playing: Some(Some(now + Duration::from_secs(10))),
+            playing: playing_for(now, Duration::from_secs(10)),
             replay_ms: 10_000,
+            delay_ms: 0,
         });
         // FF plane long stale, but the effect declared a finite replay — the declared duration is
         // the contract (a real pad honors it too), so it keeps playing…
@@ -842,26 +901,135 @@ mod ff_state_tests {
         let mut ff = ff_with(Effect {
             strong: 0x8000,
             weak: 0,
-            playing: Some(None),
+            playing: playing(now - Duration::from_millis(3000)),
             replay_ms: 0,
+            delay_ms: 0,
         });
         assert_eq!(ff.mix(now, IDLE), Some((scaled(0x8000), 0)));
         ff.last_activity = now - Duration::from_millis(3000);
         assert_eq!(ff.mix(now, IDLE), Some((0, 0)));
         // The game plays the effect again — an FF event refreshes the clock and re-arms playback.
         ff.last_activity = now;
-        ff.effects.get_mut(&0).unwrap().playing = Some(None);
+        ff.effects.get_mut(&0).unwrap().playing = playing(now);
         assert_eq!(ff.mix(now, IDLE), Some((scaled(0x8000), 0)));
     }
 
+    /// `replay.delay` shifts the whole window: silent until it elapses, then the FULL
+    /// `replay.length`. Before this the delay was decoded and dropped, so a delayed effect both
+    /// started early and finished early — DirectInput under Wine schedules these routinely.
+    #[test]
+    fn replay_delay_holds_the_effect_off_then_gives_it_its_full_length() {
+        let now = Instant::now();
+        let starts = now + Duration::from_millis(500);
+        let mut ff = ff_with(Effect {
+            strong: 0x8000,
+            weak: 0,
+            playing: Some(Playback {
+                starts,
+                ends: Some(starts + Duration::from_secs(1)),
+            }),
+            replay_ms: 1000,
+            delay_ms: 500,
+        });
+        // Inside the delay: armed but silent.
+        assert_eq!(ff.mix(now, IDLE), None);
+        assert_eq!(ff.mix(now + Duration::from_millis(499), IDLE), None);
+        // Delay elapsed: it plays.
+        assert_eq!(
+            ff.mix(now + Duration::from_millis(501), IDLE),
+            Some((scaled(0x8000), 0))
+        );
+        // Still playing at 1400 ms — it gets its full second FROM the delay, not from the play.
+        assert_eq!(ff.mix(now + Duration::from_millis(1400), IDLE), None);
+        // And ends at delay + length, not at length.
+        assert_eq!(
+            ff.mix(now + Duration::from_millis(1600), IDLE),
+            Some((0, 0))
+        );
+    }
+
+    /// The window a play opens, straight from the uploaded fields — this is the half that reads
+    /// `replay.delay` at all. Pinned separately because the `EV_FF` handler that calls it needs a
+    /// live uinput fd, so a test driving `mix` alone would pass with the delay ignored entirely.
+    #[test]
+    fn window_offsets_the_whole_playback_by_replay_delay() {
+        let at = Instant::now();
+
+        let delayed = Effect {
+            strong: 0,
+            weak: 0,
+            playing: None,
+            replay_ms: 1000,
+            delay_ms: 500,
+        };
+        let w = delayed.window(at);
+        assert_eq!(
+            w.starts,
+            at + Duration::from_millis(500),
+            "delay defers the start"
+        );
+        assert_eq!(
+            w.ends,
+            Some(at + Duration::from_millis(1500)),
+            "length runs from the END of the delay, so the effect keeps its full second"
+        );
+
+        // No delay: starts immediately, unchanged from before.
+        let plain = Effect {
+            strong: 0,
+            weak: 0,
+            playing: None,
+            replay_ms: 1000,
+            delay_ms: 0,
+        };
+        let w = plain.window(at);
+        assert_eq!(w.starts, at);
+        assert_eq!(w.ends, Some(at + Duration::from_millis(1000)));
+
+        // Length 0 = until stopped, but the delay still applies.
+        let infinite = Effect {
+            strong: 0,
+            weak: 0,
+            playing: None,
+            replay_ms: 0,
+            delay_ms: 250,
+        };
+        let w = infinite.window(at);
+        assert_eq!(w.starts, at + Duration::from_millis(250));
+        assert_eq!(w.ends, None);
+    }
+
+    /// A delayed effect must not be force-stopped as "abandoned" while it is still waiting: it has
+    /// not had its turn, and the idle window is shorter than a delay can legitimately be.
+    #[test]
+    fn a_waiting_effect_is_not_cut_by_the_idle_watchdog() {
+        let now = Instant::now();
+        let starts = now + Duration::from_secs(5);
+        let mut ff = ff_with(Effect {
+            strong: 0x8000,
+            weak: 0,
+            playing: Some(Playback { starts, ends: None }),
+            replay_ms: 0,
+            delay_ms: 5000,
+        });
+        ff.last_activity = now - Duration::from_secs(60); // long stale
+        assert_eq!(ff.mix(now, IDLE), None); // silent, but NOT cut
+                                             // It still plays when its delay elapses.
+        assert_eq!(
+            ff.mix(now + Duration::from_millis(5001), IDLE),
+            Some((scaled(0x8000), 0))
+        );
+    }
+
     #[test]
     fn disabled_watchdog_never_cuts() {
         let now = Instant::now();
         let mut ff = ff_with(Effect {
             strong: 0x8000,
             weak: 0,
-            playing: Some(None),
+            playing: playing(now),
             replay_ms: 0,
+            delay_ms: 0,
         });
         ff.last_activity = now - Duration::from_secs(600);
         assert_eq!(ff.mix(now, None), Some((scaled(0x8000), 0)));

crates/pf-inject/src/inject/linux/libei.rs

@@ -1022,10 +1022,21 @@ impl EiState {
             // Track held state on the wire codes so `release_all` can undo it at
             // session end (vanished clients must not leave anything latched).
             match ev.kind {
-                InputKind::KeyDown if !self.held_keys.contains(&ev.code) => {
-                    self.held_keys.push(ev.code);
+                // Track the code we ACTUALLY INJECTED, not the raw wire code.
+                //
+                // Injection truncates (`vk_to_evdev(ev.code as u8)`), so 0x41, 0x141, 0x241 … all
+                // press the same key — but this list stored the full 32 bits, so a KeyUp for 0x41
+                // never matched the entry a KeyDown for 0x141 left behind. A client sending
+                // distinct high bytes therefore appended entries that could never be removed, to a
+                // `Vec` scanned linearly on every keystroke, for the lifetime of the injector
+                // thread — which outlives the session (2026-08-05 review L-4). Tracking the
+                // truncated code makes the list correct AND bounds it at 256 entries by
+                // construction. `release_all` re-injects through the same truncation, so the
+                // release path is unchanged.
+                InputKind::KeyDown if !self.held_keys.contains(&(ev.code & 0xff)) => {
+                    self.held_keys.push(ev.code & 0xff);
                 }
-                InputKind::KeyUp => self.held_keys.retain(|&c| c != ev.code),
+                InputKind::KeyUp => self.held_keys.retain(|&c| c != ev.code & 0xff),
                 InputKind::MouseButtonDown if !self.held_buttons.contains(&ev.code) => {
                     self.held_buttons.push(ev.code);
                 }

crates/pf-inject/src/inject/linux/steam_controller.rs

@@ -23,6 +23,11 @@ use super::steam_proto::{
     btn, parse_steam_output, sc_from_gamepad, serial_reply, serialize_deck_state,
     serialize_sc_state, SteamModel, SteamState, STEAMDECK_RDESC, STEAM_REPORT_LEN, STEAM_VENDOR,
 };
+use crate::uhid_abi::{
+    put_cstr, request_id, set_report_data, BUS_USB, HID_MAX_DESCRIPTOR_SIZE, UHID_CREATE2,
+    UHID_DESTROY, UHID_EVENT_SIZE, UHID_GET_REPORT, UHID_GET_REPORT_REPLY, UHID_INPUT2,
+    UHID_OUTPUT, UHID_PATH, UHID_SET_REPORT, UHID_SET_REPORT_REPLY,
+};
 use crate::uhid_manager::{PadFeedback, PadProto, UhidManager};
 use anyhow::{Context, Result};
 use punktfunk_core::quic::RichInput;
@@ -32,20 +37,6 @@ use std::os::unix::fs::OpenOptionsExt;
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::time::{Duration, Instant};
 
-// /dev/uhid event ABI — same layout as the DualSense backend.
-const UHID_PATH: &str = "/dev/uhid";
-const UHID_DESTROY: u32 = 1;
-const UHID_OUTPUT: u32 = 6;
-const UHID_GET_REPORT: u32 = 9;
-const UHID_GET_REPORT_REPLY: u32 = 10;
-const UHID_CREATE2: u32 = 11;
-const UHID_INPUT2: u32 = 12;
-const UHID_SET_REPORT: u32 = 13;
-const UHID_SET_REPORT_REPLY: u32 = 14;
-const HID_MAX_DESCRIPTOR_SIZE: usize = 4096;
-const UHID_EVENT_SIZE: usize = 4 + 4372;
-const BUS_USB: u16 = 0x03;
-
 /// Hold the `b9.6` mode-switch this long at creation to toggle `gamepad_mode` on (the kernel needs
 /// ~450 ms continuous; give margin).
 const MODE_ENTER: Duration = Duration::from_millis(650);
@@ -53,11 +44,6 @@ const MODE_ENTER: Duration = Duration::from_millis(650);
 /// we insert a one-frame release so an in-game long-Start-hold can't toggle `gamepad_mode` off.
 const MENU_HOLD_CAP: Duration = Duration::from_millis(350);
 
-fn put_cstr(ev: &mut [u8], off: usize, cap: usize, s: &str) {
-    let n = s.len().min(cap - 1);
-    ev[off..off + n].copy_from_slice(&s.as_bytes()[..n]);
-}
-
 /// Best-effort, once per process: clear `hid_steam`'s `lizard_mode` so `steam_do_deck_input_event`
 /// stops gating on `gamepad_mode` (gamepad events then always flow). Needs root; on failure the
 /// per-pad `b9.6` pulse + guard handle it instead.
@@ -214,10 +200,13 @@ impl SteamDeckPad {
                     let _ = self.reply_get_report(id, &serial_reply("PUNKTFUNK01"));
                 }
                 UHID_SET_REPORT => {
-                    let id = u32::from_ne_bytes([ev[4], ev[5], ev[6], ev[7]]);
-                    // SET_REPORT data: [report-id 0, cmd, …] at ev[12..]. Surface rumble, then ack.
-                    let end = (12 + 16).min(UHID_EVENT_SIZE);
-                    if let Some(r) = parse_steam_output(&ev[12..end]).rumble {
+                    let id = request_id(&ev);
+                    // SET_REPORT data: [report-id 0, cmd, …]. Take exactly the bytes the kernel
+                    // declared — this used to read a fixed 16-byte window, which truncated any
+                    // longer report and, for a shorter one, fed the parser whatever the reused
+                    // event buffer still held past the payload. Every sibling backend that parses
+                    // SET_REPORT already read the size field; this one didn't.
+                    if let Some(r) = parse_steam_output(set_report_data(&ev)).rumble {
                         rumble = Some(r);
                     }
                     let _ = self.reply_set_report(id);

crates/pf-inject/src/inject/linux/steam_controller2.rs

@@ -23,6 +23,11 @@ use super::triton_proto::{
     triton_serial, triton_unit_id, TritonState, TRITON_RDESC, TRITON_STATE_LEN, TRITON_VENDOR,
     TRITON_WIRED_PRODUCT,
 };
+use crate::uhid_abi::{
+    put_cstr, BUS_USB, HID_MAX_DESCRIPTOR_SIZE, UHID_CREATE2, UHID_DESTROY, UHID_EVENT_SIZE,
+    UHID_GET_REPORT, UHID_GET_REPORT_REPLY, UHID_INPUT2, UHID_OUTPUT, UHID_PATH, UHID_SET_REPORT,
+    UHID_SET_REPORT_REPLY,
+};
 use crate::uhid_manager::{PadFeedback, PadProto, UhidManager};
 use anyhow::{Context, Result};
 use punktfunk_core::quic::{HidOutput, RichInput, HID_RAW_FEATURE, HID_RAW_OUTPUT};
@@ -30,25 +35,6 @@ use std::fs::{File, OpenOptions};
 use std::io::{Read, Write};
 use std::os::unix::fs::OpenOptionsExt;
 
-// /dev/uhid event ABI — same layout as the Deck/DualSense backends.
-const UHID_PATH: &str = "/dev/uhid";
-const UHID_DESTROY: u32 = 1;
-const UHID_OUTPUT: u32 = 6;
-const UHID_GET_REPORT: u32 = 9;
-const UHID_GET_REPORT_REPLY: u32 = 10;
-const UHID_CREATE2: u32 = 11;
-const UHID_INPUT2: u32 = 12;
-const UHID_SET_REPORT: u32 = 13;
-const UHID_SET_REPORT_REPLY: u32 = 14;
-const HID_MAX_DESCRIPTOR_SIZE: usize = 4096;
-const UHID_EVENT_SIZE: usize = 4 + 4372;
-const BUS_USB: u16 = 0x03;
-
-fn put_cstr(ev: &mut [u8], off: usize, cap: usize, s: &str) {
-    let n = s.len().min(cap - 1);
-    ev[off..off + n].copy_from_slice(&s.as_bytes()[..n]);
-}
-
 /// A virtual Steam Controller 2 backed by `/dev/uhid`. Dropping it destroys the device.
 pub struct TritonPad {
     fd: File,

crates/pf-inject/src/inject/linux/switch_pro.rs

@@ -22,6 +22,10 @@ use super::switch_proto::{
     serialize_report_0x30, spi_flash_read, switch_mac, SwitchOutput, SwitchState, PROCON_RDESC,
     SWITCH_PRODUCT, SWITCH_REPORT_LEN, SWITCH_VENDOR,
 };
+use crate::uhid_abi::{
+    put_cstr, BUS_USB, HID_MAX_DESCRIPTOR_SIZE, UHID_CREATE2, UHID_DESTROY, UHID_EVENT_SIZE,
+    UHID_GET_REPORT, UHID_GET_REPORT_REPLY, UHID_INPUT2, UHID_OUTPUT, UHID_PATH,
+};
 use crate::uhid_manager::{PadFeedback, PadProto, UhidManager};
 use anyhow::{Context, Result};
 use punktfunk_core::quic::{HidOutput, RichInput};
@@ -29,24 +33,6 @@ use std::fs::{File, OpenOptions};
 use std::io::{Read, Write};
 use std::os::unix::fs::OpenOptionsExt;
 
-// /dev/uhid event ABI (linux/uhid.h) — identical to the DualSense backend's; see `super::dualsense`.
-const UHID_PATH: &str = "/dev/uhid";
-const UHID_DESTROY: u32 = 1;
-const UHID_OUTPUT: u32 = 6;
-const UHID_GET_REPORT: u32 = 9;
-const UHID_GET_REPORT_REPLY: u32 = 10;
-const UHID_CREATE2: u32 = 11;
-const UHID_INPUT2: u32 = 12;
-const HID_MAX_DESCRIPTOR_SIZE: usize = 4096;
-const UHID_EVENT_SIZE: usize = 4 + 4372; // type + union (create2)
-const BUS_USB: u16 = 0x03;
-
-/// Copy a NUL-padded C string field into the event buffer.
-fn put_cstr(ev: &mut [u8], off: usize, cap: usize, s: &str) {
-    let n = s.len().min(cap - 1);
-    ev[off..off + n].copy_from_slice(&s.as_bytes()[..n]); // rest already zero (NUL-terminated)
-}
-
 /// A virtual Pro Controller backed by `/dev/uhid`. Dropping it destroys the device (the kernel
 /// tears down the bound `hid-nintendo` interface).
 pub struct SwitchProPad {

crates/pf-inject/src/inject/linux/uhid_abi.rs

@@ -0,0 +1,143 @@
+//! The `/dev/uhid` event ABI (`linux/uhid.h`), in one place.
+//!
+//! Every UHID gamepad backend — DualSense, DualShock 4, Switch Pro, Steam Controller and Steam
+//! Controller 2 — speaks the same kernel protocol, and each carried its own verbatim copy of these
+//! constants plus its own `put_cstr`. Five copies of one kernel ABI is five chances to drift from
+//! it, and they already had: `switch_pro` was missing the SET_REPORT pair entirely, and one backend
+//! read a fixed-size SET_REPORT payload instead of the length the kernel gave it (see
+//! [`set_report_data`]).
+//!
+//! `struct uhid_event` is `__packed__`: a `u32` `type` followed by a union whose largest member is
+//! `uhid_create2_req` (name 128 + phys 64 + uniq 64 + rd_size 2 + bus 2 + 4×u32 + rd_data 4096 =
+//! 4372 bytes). Nothing here allocates or parses a whole event — the backends still drive their own
+//! read/write loops; this module owns the numbers and the two field accessors that are easy to get
+//! subtly wrong.
+
+/// The character device every backend opens.
+pub const UHID_PATH: &str = "/dev/uhid";
+
+// Event types (`enum uhid_event_type`). Only the ones the backends actually use.
+pub const UHID_DESTROY: u32 = 1;
+pub const UHID_OUTPUT: u32 = 6;
+pub const UHID_GET_REPORT: u32 = 9;
+pub const UHID_GET_REPORT_REPLY: u32 = 10;
+pub const UHID_CREATE2: u32 = 11;
+pub const UHID_INPUT2: u32 = 12;
+pub const UHID_SET_REPORT: u32 = 13;
+pub const UHID_SET_REPORT_REPLY: u32 = 14;
+
+/// `HID_MAX_DESCRIPTOR_SIZE` — also the cap on a report payload we will copy out of an event.
+pub const HID_MAX_DESCRIPTOR_SIZE: usize = 4096;
+/// `size_of::<uhid_event>()`: the `u32` type tag plus the create2 union.
+pub const UHID_EVENT_SIZE: usize = 4 + 4372;
+/// `BUS_USB` from `linux/input.h`.
+pub const BUS_USB: u16 = 0x03;
+
+/// Offset of the `id` field shared by the GET_REPORT / SET_REPORT request and reply structs.
+const OFF_ID: usize = 4;
+/// Offset of `uhid_set_report_req::size` (after `id: u32`, `rnum: u8`, `rtype: u8`).
+const OFF_SET_REPORT_SIZE: usize = 10;
+/// Offset of the payload in a SET_REPORT request — and of `data` in the reply structs.
+const OFF_DATA: usize = 12;
+/// Offset of `uhid_output_req::size` (the payload follows `data[4096]`).
+const OFF_OUTPUT_SIZE: usize = 4 + HID_MAX_DESCRIPTOR_SIZE;
+
+/// Copy a NUL-padded C string field into the event buffer. The buffer is zeroed by the caller, so
+/// truncation still leaves a NUL terminator.
+pub fn put_cstr(ev: &mut [u8], off: usize, cap: usize, s: &str) {
+    let n = s.len().min(cap - 1);
+    ev[off..off + n].copy_from_slice(&s.as_bytes()[..n]); // rest already zero (NUL-terminated)
+}
+
+/// The request id of a GET_REPORT / SET_REPORT event — what the matching reply must echo.
+pub fn request_id(ev: &[u8]) -> u32 {
+    u32::from_ne_bytes([ev[OFF_ID], ev[OFF_ID + 1], ev[OFF_ID + 2], ev[OFF_ID + 3]])
+}
+
+/// The payload of a `UHID_SET_REPORT` event: exactly the bytes the kernel says are there.
+///
+/// Read the length from the event's own `size` field. Assuming a fixed window instead is wrong in
+/// both directions — a longer report is silently truncated, and a shorter one is parsed together
+/// with whatever stale bytes the reused event buffer still holds past its end, which for a rumble
+/// report means acting on numbers the game never wrote.
+pub fn set_report_data(ev: &[u8]) -> &[u8] {
+    let size = u16::from_ne_bytes([ev[OFF_SET_REPORT_SIZE], ev[OFF_SET_REPORT_SIZE + 1]]) as usize;
+    let end = (OFF_DATA + size.min(HID_MAX_DESCRIPTOR_SIZE)).min(ev.len());
+    &ev[OFF_DATA.min(end)..end]
+}
+
+/// The payload of a `UHID_OUTPUT` event (`uhid_output_req`: `data[4096]` then `size`).
+pub fn output_data(ev: &[u8]) -> &[u8] {
+    let size = u16::from_ne_bytes([ev[OFF_OUTPUT_SIZE], ev[OFF_OUTPUT_SIZE + 1]]) as usize;
+    let end = (4 + size.min(HID_MAX_DESCRIPTOR_SIZE)).min(ev.len());
+    &ev[4.min(end)..end]
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn blank() -> Vec<u8> {
+        vec![0u8; UHID_EVENT_SIZE]
+    }
+
+    #[test]
+    fn set_report_data_honours_the_events_own_size() {
+        let mut ev = blank();
+        ev[OFF_SET_REPORT_SIZE..OFF_SET_REPORT_SIZE + 2].copy_from_slice(&5u16.to_ne_bytes());
+        for (i, b) in [1u8, 2, 3, 4, 5].iter().enumerate() {
+            ev[OFF_DATA + i] = *b;
+        }
+        // Stale bytes past the payload — a fixed-window read would hand these to the parser.
+        ev[OFF_DATA + 5] = 0xAA;
+        ev[OFF_DATA + 15] = 0xBB;
+        assert_eq!(set_report_data(&ev), &[1, 2, 3, 4, 5]);
+    }
+
+    #[test]
+    fn set_report_data_is_not_truncated_at_sixteen() {
+        let mut ev = blank();
+        let n = 40usize;
+        ev[OFF_SET_REPORT_SIZE..OFF_SET_REPORT_SIZE + 2].copy_from_slice(&(n as u16).to_ne_bytes());
+        for i in 0..n {
+            ev[OFF_DATA + i] = i as u8;
+        }
+        let d = set_report_data(&ev);
+        assert_eq!(
+            d.len(),
+            n,
+            "a report longer than 16 bytes must survive whole"
+        );
+        assert_eq!(d[39], 39);
+    }
+
+    #[test]
+    fn oversized_and_empty_sizes_stay_in_bounds() {
+        let mut ev = blank();
+        ev[OFF_SET_REPORT_SIZE..OFF_SET_REPORT_SIZE + 2].copy_from_slice(&u16::MAX.to_ne_bytes());
+        assert!(set_report_data(&ev).len() <= HID_MAX_DESCRIPTOR_SIZE);
+        assert!(OFF_DATA + set_report_data(&ev).len() <= UHID_EVENT_SIZE);
+
+        let ev0 = blank(); // size = 0
+        assert!(set_report_data(&ev0).is_empty());
+        assert!(output_data(&ev0).is_empty());
+    }
+
+    #[test]
+    fn output_data_reads_its_trailing_size_field() {
+        let mut ev = blank();
+        ev[OFF_OUTPUT_SIZE..OFF_OUTPUT_SIZE + 2].copy_from_slice(&3u16.to_ne_bytes());
+        ev[4] = 0x02;
+        ev[5] = 0x11;
+        ev[6] = 0x22;
+        ev[7] = 0x33; // past the declared size
+        assert_eq!(output_data(&ev), &[0x02, 0x11, 0x22]);
+    }
+
+    #[test]
+    fn request_id_round_trips() {
+        let mut ev = blank();
+        ev[OFF_ID..OFF_ID + 4].copy_from_slice(&0xDEAD_BEEFu32.to_ne_bytes());
+        assert_eq!(request_id(&ev), 0xDEAD_BEEF);
+    }
+}

crates/pf-inject/src/inject/proto/dualsense_proto.rs

@@ -250,11 +250,19 @@ impl DsState {
         use punktfunk_core::input::gamepad as gs;
         let to_u8 = |v: i16| (((v as i32) + 32768) >> 8) as u8;
         let on = |bit: u32| buttons & bit != 0;
+        // Invert in i16 space, BEFORE the quantisation, rather than as `255 - to_u8(v)`.
+        // 0..=255 has no exact midpoint: `to_u8` puts centre at 0x80, which leaves 128 codes below
+        // it and 127 above, so mirroring the *output* (`255 - 0x80` = 0x7F) lands a centred stick
+        // one LSB off the 0x80 that `DsState::neutral` — and the pad's own resting report — use.
+        // Games idle-poll a centred stick constantly, so that off-by-one showed up as a permanent
+        // sub-deadzone tilt on the Y axes only. Negating first maps centre to centre by
+        // construction and keeps both extremes exact (+32767 → 0, -32768 → 255); the only cost is
+        // that i16::MIN and -32767 share the 255 code, one LSB at the very end of the travel.
         let mut s = DsState {
             lx: to_u8(lx),
-            ly: 255 - to_u8(ly),
+            ly: to_u8(ly.saturating_neg()),
             rx: to_u8(rx),
-            ry: 255 - to_u8(ry),
+            ry: to_u8(ry.saturating_neg()),
             l2: lt,
             r2: rt,
             ..DsState::neutral()
@@ -471,7 +479,14 @@ fn pack_touch(dst: &mut [u8], t: &Touch) {
 #[derive(Default)]
 pub struct DsFeedback {
     pub hidout: Vec<HidOutput>,
-    /// `(low, high)` motor levels (0..=0xFFFF), if a report carried them.
+    /// `(low, high)` motor levels, if a report carried them.
+    ///
+    /// This parser widens the device's 8-bit motor bytes by `<< 8`, so the values it produces are
+    /// `0..=0xFF00` in steps of 0x100 — NOT `0..=0xFFFF`, which is what this said before. The
+    /// Windows backend widens the same bytes by `× 257` and does reach 0xFFFF. Both are correct:
+    /// every consumer narrows with `>> 8`, and 0xFF00 and 0xFFFF both narrow back to 255. Do not
+    /// "fix" one to match the other — see [`crate::uhid_manager::PadFeedback::rumble`], which is
+    /// the type that sees both.
     pub rumble: Option<(u16, u16)>,
     /// The driver's output-report ring overflowed this poll — pending reports were DISCARDED and
     /// feedback state is unknown; the [`UhidManager`](crate::uhid_manager) must resync (silence +
@@ -479,67 +494,119 @@ pub struct DsFeedback {
     pub resync: bool,
 }
 
-/// Parse a DualSense USB output report (`0x02`) into a [`DsFeedback`]. The byte layout below is
-/// the USB DualSense common report; only the well-understood fields (motor rumble, lightbar RGB,
-/// player LEDs) are surfaced — adaptive-trigger blocks are forwarded raw for the client.
+/// Field offsets in the DualSense **output** report, as indices into a whole USB report — i.e.
+/// including the leading report id at `[0]`. This is the one place in Rust the layout is written
+/// down; index off these rather than repeating the numbers.
+///
+/// **The same fields sit at different offsets per transport, and that is not drift.** Every writer
+/// lays out one common block; what changes is how much header precedes it:
+///
+/// | base | where | first payload byte |
+/// |---|---|---|
+/// | `0`  | USB report, id included — what these constants describe, and what this parser reads | `[1]` |
+/// | `−1` | SDL `DS5EffectsState_t` — a 47-byte payload with NO report id (`pf-client-core`'s `Ds5Feedback`) | `[0]` |
+/// | `+2` | Bluetooth report `0x31` — id, sequence, magic, then the block; CRC32 in the last 4 bytes | `[3]` |
+///
+/// Subtract or add the base to translate. Mirrors that cannot import this module — Kotlin
+/// (`DsDevice.kt`, USB base 0) and Swift (`DualSenseHID.swift`, which handles both the USB and
+/// Bluetooth bases) — carry a pointer back here; keep them in step by hand.
+pub mod out_report {
+    /// `valid_flag0`: BIT0 compat vibration, BIT1 haptics select, BIT2 R2, BIT3 L2.
+    pub const VALID_FLAG0: usize = 1;
+    /// `valid_flag1`: BIT2 lightbar, BIT4 player indicators.
+    pub const VALID_FLAG1: usize = 2;
+    /// High-frequency (small / right) motor.
+    pub const MOTOR_RIGHT: usize = 3;
+    /// Low-frequency (big / left) motor.
+    pub const MOTOR_LEFT: usize = 4;
+    /// First byte of the RIGHT trigger's parameter block — it precedes the left one in the report.
+    pub const RIGHT_TRIGGER: usize = 11;
+    /// First byte of the LEFT trigger's parameter block.
+    pub const LEFT_TRIGGER: usize = 22;
+    /// One adaptive-trigger parameter block: a mode byte plus 10 parameters.
+    pub const TRIGGER_LEN: usize = 11;
+    /// `valid_flag2`: BIT2 = `COMPATIBLE_VIBRATION2` (the firmware ≥ 2.24 rumble signal).
+    pub const VALID_FLAG2: usize = 39;
+    /// Lit player-indicator bits (low 5).
+    pub const PLAYER_LEDS: usize = 44;
+    /// Lightbar red; green and blue follow.
+    pub const LED_RGB: usize = 45;
+}
+
+/// Parse a DualSense USB output report (`0x02`) into a [`DsFeedback`], indexed off
+/// [`out_report`]. Only the well-understood fields (motor rumble, lightbar RGB, player LEDs) are
+/// surfaced — adaptive-trigger blocks and the audio-control region are forwarded raw for the client.
 ///
 /// Every field is gated on the report's valid-flags (`valid_flag0` at data[1], `valid_flag1`
 /// at data[2]) — writers only set the bits for fields they mean to change (the rest is zeroed),
 /// so an ungated parse would turn every plain rumble write into a lightbar-off + triggers-off
 /// broadcast.
 pub fn parse_ds_output(pad: u8, data: &[u8], fb: &mut DsFeedback) {
+    use out_report as o;
     // data[0] is the report id (0x02). Be defensive about short reports.
     if data.first() != Some(&0x02) || data.len() < 48 {
         return;
     }
-    let flag0 = data[1]; // BIT0 compat vibration, BIT1 haptics select, BIT2 R2, BIT3 L2
-    let flag1 = data[2]; // BIT2 lightbar, BIT4 player indicators
-                         // Motor rumble: high-frequency (small/right) motor at data[3], low-frequency (big/left) at
-                         // data[4]. Scale 0..255 → 0..0xFFFF, same (low, high) convention as the uinput pad's mixer,
-                         // and route to the universal rumble plane (0xCA).
-                         // Writers on firmware ≥ 2.24 signal rumble via COMPATIBLE_VIBRATION2 in valid_flag2
-                         // (data[39] BIT2) instead of flag0 BIT0. Our feature report advertises a version
-                         // above 2.24 (DS_FEATURE_FIRMWARE bytes 44..46, chosen to keep Sony's updater
-                         // quiet), so the kernel and SDL write the v2 flag — while older writers, and any
-                         // that never read the version, stay on flag0. Both conventions must land here: a
-                         // rumble dropped on either — including stops — is silently ignored, and a missed
-                         // stop buzzes for the rest of the session (the 500 ms refresh re-sends stale state
-                         // forever).
-    if flag0 & 0x03 != 0 || data[39] & 0x04 != 0 {
-        let high = (data[3] as u16) << 8;
-        let low = (data[4] as u16) << 8;
+    let flag0 = data[o::VALID_FLAG0]; // BIT0 compat vibration, BIT1 haptics select, BIT2 R2, BIT3 L2
+    let flag1 = data[o::VALID_FLAG1]; // BIT2 lightbar, BIT4 player indicators
+                                      // Motor rumble: high-frequency (small/right) motor first, low-frequency (big/left) second.
+                                      // Widened 0..255 → 0..0xFF00 by `<< 8` (NOT 0xFFFF — see `DsFeedback::rumble`), same
+                                      // (low, high) convention as the uinput pad's mixer, and routed to the 0xCA plane.
+                                      // Writers on firmware ≥ 2.24 signal rumble via COMPATIBLE_VIBRATION2 in valid_flag2
+                                      // instead of flag0 BIT0. Our feature report advertises a version above 2.24
+                                      // (DS_FEATURE_FIRMWARE bytes 44..46, chosen to keep Sony's updater quiet), so the
+                                      // kernel and SDL write the v2 flag — while older writers, and any that never read the
+                                      // version, stay on flag0. Both conventions must land here: a rumble dropped on either
+                                      // — including stops — is silently ignored, and a missed stop buzzes for the rest of
+                                      // the session (the 500 ms refresh re-sends stale state forever).
+    if flag0 & 0x03 != 0 || data[o::VALID_FLAG2] & 0x04 != 0 {
+        let high = (data[o::MOTOR_RIGHT] as u16) << 8;
+        let low = (data[o::MOTOR_LEFT] as u16) << 8;
         fb.rumble = Some((low, high));
     }
-    // Lightbar RGB (USB common report: bytes 45..48). Player LEDs at byte 44.
     if flag1 & 0x04 != 0 {
-        let (r, g, b) = (data[45], data[46], data[47]);
+        let (r, g, b) = (data[o::LED_RGB], data[o::LED_RGB + 1], data[o::LED_RGB + 2]);
         fb.hidout.push(HidOutput::Led { pad, r, g, b });
     }
     if flag1 & 0x10 != 0 {
         fb.hidout.push(HidOutput::PlayerLeds {
             pad,
-            bits: data[44] & 0x1F,
+            bits: data[o::PLAYER_LEDS] & 0x1F,
         });
     }
-    // Adaptive-trigger parameter blocks, 11 bytes each: the RIGHT trigger comes FIRST in the
-    // report (bytes 11..22), the left at 22..33 — per SDL's DS5EffectsState_t / inputtino's
-    // ps5.hpp. Wire convention: which 0 = L2, 1 = R2.
-    if data.len() >= 33 {
+    // The RIGHT trigger block comes FIRST in the report — per SDL's DS5EffectsState_t /
+    // inputtino's ps5.hpp. Wire convention: which 0 = L2, 1 = R2.
+    if data.len() >= o::LEFT_TRIGGER + o::TRIGGER_LEN {
         if flag0 & 0x04 != 0 {
             fb.hidout.push(HidOutput::Trigger {
                 pad,
                 which: 1,
-                effect: data[11..22].to_vec(),
+                effect: data[o::RIGHT_TRIGGER..o::RIGHT_TRIGGER + o::TRIGGER_LEN].to_vec(),
             });
         }
         if flag0 & 0x08 != 0 {
             fb.hidout.push(HidOutput::Trigger {
                 pad,
                 which: 0,
-                effect: data[22..33].to_vec(),
+                effect: data[o::LEFT_TRIGGER..o::LEFT_TRIGGER + o::TRIGGER_LEN].to_vec(),
             });
         }
     }
+    // The audio-control region (bytes 5..=10: headphone/speaker/mic volumes + routing), for the
+    // pad-audio path. The wire flags condense the report's audio bits: bit0 = haptics-select
+    // (flag0 BIT1 — set on every SDL rumble write too, which is why it alone never triggers an
+    // emission), bits1..4 = flag0 bits 4..7 (the audio-valid flags gating the region). Emitted
+    // whenever an audio-valid flag is present or the region carries data; downstream dedup
+    // ([`crate::hidout_dedup`]) reduces the per-report repeats to genuine changes.
+    let raw: [u8; 6] = data[5..11].try_into().unwrap();
+    if flag0 & 0xF0 != 0 || raw != [0u8; 6] {
+        let flags = ((flag0 >> 1) & 0x01) | ((flag0 >> 3) & 0x1E);
+        fb.hidout.push(HidOutput::AudioCtl {
+            pad: pad.into(),
+            flags,
+            raw,
+        });
+    }
 }
 
 #[cfg(test)]
@@ -783,6 +850,29 @@ mod tests {
         assert_eq!(r[53], 0x0A);
     }
 
+    /// A centred stick must encode as the pad's own neutral on BOTH axes. Inverting the quantised
+    /// byte (`255 - v`) put Y one LSB below it, which games idle-poll constantly — a permanent
+    /// sub-deadzone tilt. Extremes must stay exact either way.
+    #[test]
+    fn centred_sticks_encode_as_neutral_on_every_axis() {
+        let n = DsState::neutral();
+        let s = DsState::from_gamepad(0, 0, 0, 0, 0, 0, 0);
+        assert_eq!((s.lx, s.ly), (n.lx, n.ly), "left stick centre");
+        assert_eq!((s.rx, s.ry), (n.rx, n.ry), "right stick centre");
+
+        // Y is still inverted (XInput +y = up, DualSense 0 = up) and both ends stay exact.
+        let up = DsState::from_gamepad(0, 0, i16::MAX, 0, i16::MAX, 0, 0);
+        assert_eq!((up.ly, up.ry), (0, 0), "full up = 0");
+        let down = DsState::from_gamepad(0, 0, i16::MIN, 0, i16::MIN, 0, 0);
+        assert_eq!((down.ly, down.ry), (255, 255), "full down = 255");
+
+        // X keeps its existing mapping.
+        let right = DsState::from_gamepad(0, i16::MAX, 0, i16::MAX, 0, 0, 0);
+        assert_eq!((right.lx, right.rx), (255, 255));
+        let left = DsState::from_gamepad(0, i16::MIN, 0, i16::MIN, 0, 0, 0);
+        assert_eq!((left.lx, left.rx), (0, 0));
+    }
+
     /// The wire touchpad-click / guide / mute bits (Moonlight's extended positions) land in
     /// `buttons[2]`.
     #[test]
@@ -842,6 +932,48 @@ mod tests {
         assert_eq!(*DUALSENSE_EDGE_RDESC.last().unwrap(), 0xC0);
     }
 
+    /// A 0x02 report driving the pad's audio (haptics-select + audio-valid flags + the volume/
+    /// routing bytes) surfaces an `AudioCtl` with the exact raw region and the condensed flags;
+    /// a plain rumble write (haptics-select but a silent audio region — every SDL rumble) does
+    /// NOT — that is what `parse_output_respects_valid_flags` pins with its `hidout.is_empty()`.
+    #[test]
+    fn parse_output_surfaces_audio_ctl() {
+        let mut data = vec![0u8; 48];
+        data[0] = 0x02;
+        data[1] = 0xB2; // flag0: haptics-select (BIT1) + audio-valid bits 4/5/7
+        data[5] = 0x50; // headphone volume
+        data[6] = 0x60; // speaker volume
+        data[7] = 0x70; // mic volume
+        data[8] = 0x05; // audio routing / enable bits
+        let mut fb = DsFeedback::default();
+        parse_ds_output(3, &data, &mut fb);
+        // flags: bit0 = flag0 bit1, bits1..4 = flag0 bits 4..7 (0b1011 → 0b10110).
+        assert_eq!(
+            fb.hidout,
+            vec![HidOutput::AudioCtl {
+                pad: 3,
+                flags: 0b1_0111,
+                raw: [0x50, 0x60, 0x70, 0x05, 0x00, 0x00],
+            }]
+        );
+        // A non-zero audio region with NO audio-valid flags still surfaces (dedup collapses the
+        // repeats downstream) — some writers leave stale volumes gated off; the host side wants
+        // the honest bytes either way.
+        let mut data = vec![0u8; 48];
+        data[0] = 0x02;
+        data[9] = 0x01;
+        let mut fb = DsFeedback::default();
+        parse_ds_output(0, &data, &mut fb);
+        assert_eq!(
+            fb.hidout,
+            vec![HidOutput::AudioCtl {
+                pad: 0,
+                flags: 0,
+                raw: [0, 0, 0, 0, 0x01, 0],
+            }]
+        );
+    }
+
     /// A short / wrong-id report yields nothing.
     #[test]
     fn parse_output_rejects_garbage() {

crates/pf-inject/src/inject/proto/steam_proto.rs

@@ -183,8 +183,9 @@ impl SteamState {
 
     /// Map an `XInput`/GameStream pad frame (button bitmask + i16 sticks + u8 triggers) into the Deck
     /// state. Sticks pass through (the kernel negates Y, which yields the conventional direction —
-    /// validated on-box); triggers scale u8 0..255 → u16 0..32640 and set the full-pull bit when
-    /// pressed. Trackpad + motion + the back grips arrive separately ([`apply_rich`], the M3 wire).
+    /// validated on-box); triggers scale u8 0..255 → u16 0..32767 ([`trigger_u16`]) and set the
+    /// full-pull bit when pressed. Trackpad + motion + the back grips arrive separately
+    /// ([`apply_rich`], the M3 wire).
     pub fn from_gamepad(
         buttons: u32,
         lx: i16,
@@ -200,8 +201,8 @@ impl SteamState {
             ly,
             rx,
             ry,
-            lt: (lt as u16) * 128,
-            rt: (rt as u16) * 128,
+            lt: trigger_u16(lt),
+            rt: trigger_u16(rt),
             ..SteamState::neutral()
         };
         let mut b = 0u64;
@@ -375,8 +376,8 @@ pub fn sc_from_gamepad(
         ly,
         rx: 0,
         ry: 0,
-        lt: (lt as u16) * 128,
-        rt: (rt as u16) * 128,
+        lt: trigger_u16(lt),
+        rt: trigger_u16(rt),
         // The wire right stick becomes a right-pad contact (see the doc above).
         rpad_x: rx,
         rpad_y: ry,
@@ -466,6 +467,18 @@ pub fn serialize_sc_state(r: &mut [u8; STEAM_REPORT_LEN], st: &SteamState, seq:
     r[38..40].copy_from_slice(&st.gyro[2].to_le_bytes());
 }
 
+/// Scale a wire trigger (u8 `0..=255`) onto the Deck's full axis (u16 `0..=32767`).
+///
+/// This was `v * 128`, which tops out at 32640 — a fully-pulled trigger reported 99.6% and the top
+/// 127 counts of the declared range were unreachable, so a game reading the axis could never see a
+/// true full pull. One multiply gets both ends exact (`0 → 0`, `255 → 32767`) and stays monotonic.
+///
+/// `serialize_report`'s inverse (`>> 7`, for the legacy u8 trigger bytes) still round-trips both
+/// ends against this: `32767 >> 7 == 255`.
+fn trigger_u16(v: u8) -> u16 {
+    ((v as u32 * 32767) / 255) as u16
+}
+
 /// Build the `steam_get_serial` GET_REPORT reply. The Steam feature path is report-id-0 with a
 /// leading report-id byte the kernel strips (`steam_recv_report` does `memcpy(data, buf+1, …)`), so
 /// the wire is `[0x00, 0xAE, len, 0x01, ascii…]`; the kernel then validates `reply[0]==0xAE`,
@@ -473,7 +486,12 @@ pub fn serialize_sc_state(r: &mut [u8; STEAM_REPORT_LEN], st: &SteamState, seq:
 pub fn serial_reply(serial: &str) -> [u8; STEAM_REPORT_LEN] {
     let mut buf = [0u8; STEAM_REPORT_LEN];
     let bytes = serial.as_bytes();
-    let len = bytes.len().clamp(1, 21);
+    // `min`, not `clamp(1, 21)`. Clamping the LOW end to 1 and then slicing `bytes[..len]` asks a
+    // zero-byte slice for one byte, which panics — on the service thread, for an input the kernel
+    // already has a graceful answer to. Reporting the true length lets its own validation
+    // (`1 <= reply[1] <= 21`) reject an empty serial and fall back to "XXXXXXXXXX", which is the
+    // documented behaviour for a reply it does not like.
+    let len = bytes.len().min(21);
     buf[0] = 0x00; // report id 0 — stripped by steam_recv_report
     buf[1] = ID_GET_STRING_ATTRIBUTE;
     buf[2] = len as u8;
@@ -704,7 +722,7 @@ mod tests {
         assert_ne!(s.buttons & btn::STEAM, 0);
         assert_ne!(s.buttons & btn::LB, 0);
         assert_ne!(s.buttons & btn::LT_FULL, 0); // lt=255 → full-pull bit
-        assert_eq!(s.lt, 255 * 128);
+        assert_eq!(s.lt, 32767); // full pull reaches the TOP of the declared range
         assert_eq!(s.lx, 1000);
         assert_eq!(s.ly, -2000);
 
@@ -730,6 +748,30 @@ mod tests {
         assert_eq!(s.accel, [16384, -8192, 0]);
     }
 
+    /// An empty serial must not panic. `clamp(1, 21)` asked a zero-byte slice for one byte, which
+    /// is an out-of-range slice index — on the service thread. The kernel rejects a zero length by
+    /// its own rule (`1 <= reply[1] <= 21`) and falls back, which is the graceful answer.
+    #[test]
+    fn empty_serial_reply_does_not_panic() {
+        let r = serial_reply("");
+        assert_eq!(r[1], ID_GET_STRING_ATTRIBUTE);
+        assert_eq!(
+            r[2], 0,
+            "length the kernel will reject, rather than a panic"
+        );
+
+        // Normal and over-long serials still behave.
+        let r = serial_reply("ABC123");
+        assert_eq!(r[2], 6);
+        assert_eq!(&r[4..10], b"ABC123");
+        let long = "X".repeat(40);
+        assert_eq!(
+            serial_reply(&long)[2],
+            21,
+            "clamped to the protocol maximum"
+        );
+    }
+
     /// M3: the wire back-button bits map to the four Deck grips + QAM, and `TouchpadEx` routes the
     /// left / right surfaces to the matching pad (x passes straight through; y flips from the
     /// wire's screen convention (+down) to the Deck's raw +up — the live-verified direction).

crates/pf-inject/src/inject/uhid_manager.rs

@@ -18,7 +18,12 @@ use std::time::{Duration, Instant};
 /// 0xCD feedback events (lightbar / player LEDs / adaptive triggers), deduped via [`HidoutDedup`].
 #[derive(Default)]
 pub struct PadFeedback {
-    /// `(low, high)` motor levels (0..=0xFF00), if the pass saw a rumble report.
+    /// `(low, high)` motor levels, if the pass saw a rumble report.
+    ///
+    /// Range is `0..=0xFFFF` — this said `0..=0xFF00`, which is only true of the backends that
+    /// widen the device's 8-bit motor byte by `<< 8` (the UHID/DualSense path). The Windows
+    /// backend widens by `× 257` and does reach 0xFFFF, and this type carries both. Neither is a
+    /// defect: consumers narrow with `>> 8`, and 0xFF00 and 0xFFFF both narrow back to 255.
     pub rumble: Option<(u16, u16)>,
     pub hidout: Vec<HidOutput>,
     /// Whether the game drove this pad's RUMBLE plane this poll — at least one output report
@@ -159,6 +164,22 @@ impl OverflowWarn {
 /// real firmware decays, and that re-assert is what keeps a legitimately-held long rumble alive
 /// here. The XUSB path shares this window via [`rumble_idle_timeout`] (every XUSB write IS a
 /// rumble write, so its any-activity keying is already rumble-keyed by construction).
+///
+/// KNOWN COST, deliberately accepted. That invariant only covers writers that re-assert. A game
+/// driving the pad through the kernel's *evdev* FF interface does not: `ff-memless` sends one
+/// output report when an effect starts and one when it stops, with nothing in between, so a finite
+/// effect longer than this window is cut in half here. The uinput path
+/// (`linux/gamepad.rs`) exempts exactly that case — but it can, because evdev FF hands it an
+/// explicit `replay.length`. Nothing equivalent reaches this layer: [`PadFeedback`] carries motor
+/// levels, and the protocols it speaks (DualSense / DS4 / Deck / Switch Pro) are all
+/// level-triggered with no duration field anywhere in a report. So the choice is between cutting a
+/// long finite effect and letting an abandoned residual drone forever, and the residual is the one
+/// with field evidence behind it (a stuck level resent every 500 ms for 5.5 minutes). Switch Pro is
+/// not affected either way — `hid-nintendo` re-sends rumble continuously, and a physical Pro's
+/// HD-rumble decays faster than this window regardless.
+///
+/// Do not "fix" this by widening or disabling the window without evidence about which failure real
+/// titles actually hit; the hatch below exists for exactly that experiment.
 const RUMBLE_IDLE_TIMEOUT: Duration = Duration::from_millis(2500);
 
 /// The abandoned-rumble force-off window, env-hatched: `PUNKTFUNK_RUMBLE_IDLE_MS` overrides
@@ -338,10 +359,17 @@ impl<B: PadProto> UhidManager<B> {
             for h in fb.hidout {
                 // Skip rich feedback that repeats the last-forwarded value (a game's output report
                 // re-sends unchanged lightbar/LED/trigger state alongside every rumble update).
-                if self.hidout_dedup[i].should_forward(&h) {
+                if self.hidout_dedup[i].should_forward(&h, now) {
                     hidout(h);
                 }
             }
+            // Re-assert the latched rich state on a slow cadence. Deduping a plane that rides
+            // unreliable datagrams means a dropped update is never re-derived from the game — it
+            // keeps sending the same value and the dedup eats every copy — so without this one
+            // lost datagram leaves the pad on the previous weapon's trigger effect indefinitely.
+            for h in self.hidout_dedup[i].renewals(i as u8, now) {
+                hidout(h);
+            }
         }
     }
 
@@ -490,6 +518,7 @@ mod tests {
             index: 2,
             kind: 1,
             capabilities: 0,
+            audio_caps: 0,
         });
         assert!(m.slots.get(2).is_some());
     }

crates/pf-inject/src/inject/windows/gamepad_raii.rs

@@ -819,46 +819,77 @@ impl DriverAttach {
 
     /// One-shot WARN with everything the host can find out about WHY the driver isn't attached:
     /// driver-store presence, the devnode's PnP status/problem code, and where to look next.
+    ///
+    /// Runs on its own thread and returns immediately. The caller is the session's pad service
+    /// thread — the one feeding input and rumble — and everything below is slow: the driver-store
+    /// check waits up to [`INVENTORY_WAIT`] for a `pnputil` enumeration that can take tens of
+    /// seconds, and the devnode lookup is a synchronous PnP call. Blocking there stalled input for
+    /// up to two seconds *per unattached pad* (the wait is a deadline, not a one-off: while the
+    /// enumeration is still outstanding every pad pays it again), at exactly the moment a session
+    /// is already going wrong. Diagnostics must never be able to hurt the thing they diagnose.
+    ///
+    /// Off the hot path the wait also stops being a compromise — it can afford to be patient and
+    /// report what it actually found rather than "still enumerating".
     fn diagnose(&self) {
-        let store = match driver_store_has(self.inf) {
-            Some(true) => "driver package present in the driver store",
-            Some(false) => {
-                "driver package NOT in the driver store — run: punktfunk-host.exe driver install --gamepad"
-            }
-            None => "driver store could not be queried (pnputil failed or still enumerating)",
-        };
-        let devnode = match &self.instance_id {
-            Some(id) => devnode_status_line(id),
-            None => {
-                "no per-session devnode (SwDeviceCreate failed earlier — see the warning above)"
-                    .to_string()
-            }
-        };
-        tracing::warn!(
-            driver = self.driver,
-            shm = %self.shm_name,
-            grace_secs = ATTACH_GRACE.as_secs(),
-            store,
-            devnode = %devnode,
-            driver_log = self.driver_log,
-            "gamepad driver has not attached to the shared section — the virtual pad exists but no \
-             driver is serving it (games will not see it); an old (pre-sealed-channel) driver also \
-             reads as not-attached: update with punktfunk-host.exe driver install --gamepad \
-             (driver_log is only written by debug driver builds, or with the PFXUSB_DEBUG_LOG / \
-             PFGAMEPAD_DEBUG_LOG / PFMOUSE_DEBUG_LOG system env var set + the device restarted)"
-        );
+        let (driver, inf, driver_log) = (self.driver, self.inf, self.driver_log);
+        let shm_name = self.shm_name.clone();
+        let instance_id = self.instance_id.clone();
+        std::thread::Builder::new()
+            .name("pf-driver-diagnose".into())
+            .spawn(move || diagnose_blocking(driver, inf, driver_log, &shm_name, instance_id))
+            .ok();
     }
 }
 
-/// How long [`driver_store_inventory`] lets the caller wait for the background pnputil query
-/// before reporting without it — [`observe`] runs on the pad service thread, which must keep
-/// draining pad slots even when the driver store is wedged.
-const INVENTORY_WAIT: Duration = Duration::from_secs(2);
+/// The body of [`DriverAttach::diagnose`], on its own thread. Split out rather than inlined into
+/// the closure so the blocking calls stay visible as blocking.
+fn diagnose_blocking(
+    driver: &'static str,
+    inf: &'static str,
+    driver_log: &'static str,
+    shm_name: &str,
+    instance_id: Option<String>,
+) {
+    let store = match driver_store_has(inf) {
+        Some(true) => "driver package present in the driver store",
+        Some(false) => {
+            "driver package NOT in the driver store — run: punktfunk-host.exe driver install --gamepad"
+        }
+        None => "driver store could not be queried (pnputil failed or still enumerating)",
+    };
+    let devnode = match &instance_id {
+        Some(id) => devnode_status_line(id),
+        None => "no per-session devnode (SwDeviceCreate failed earlier — see the warning above)"
+            .to_string(),
+    };
+    tracing::warn!(
+        driver,
+        shm = %shm_name,
+        grace_secs = ATTACH_GRACE.as_secs(),
+        store,
+        devnode = %devnode,
+        driver_log,
+        "gamepad driver has not attached to the shared section — the virtual pad exists but no \
+         driver is serving it (games will not see it); an old (pre-sealed-channel) driver also \
+         reads as not-attached: update with punktfunk-host.exe driver install --gamepad \
+         (driver_log is only written by debug driver builds, or with the PFXUSB_DEBUG_LOG / \
+         PFGAMEPAD_DEBUG_LOG / PFMOUSE_DEBUG_LOG system env var set + the device restarted)"
+    );
+}
+
+/// How long [`driver_store_inventory`] waits for the background pnputil query before reporting
+/// without it. Only [`diagnose_blocking`] waits, and that has a thread to itself, so this is
+/// generous: pnputil routinely takes longer than a couple of seconds on a busy driver store, and
+/// the old two-second budget — chosen to limit the damage while this ran on the pad service thread
+/// — meant the diagnosis usually gave up and printed "still enumerating", which is the one answer
+/// that helps nobody. Nothing waits on this thread, so patience costs only a late log line.
+const INVENTORY_WAIT: Duration = Duration::from_secs(30);
 
 /// Driver-store inventory (`pnputil /enum-drivers`), lower-cased, fetched once per process — only
 /// consulted on the failure path, so the subprocess cost never hits a healthy session. The query
 /// runs on its OWN thread: pnputil can block for tens of seconds on a busy/wedged driver store,
-/// and the caller is the pad service thread. `None` = not available yet (query still running) or
+/// and this keeps one wedged query from being re-run per pad. `None` = not available yet (query
+/// still running past [`INVENTORY_WAIT`]) or
 /// failed; a query that outlives [`INVENTORY_WAIT`] still lands in the cache for later reports.
 fn driver_store_inventory() -> Option<&'static str> {
     static INV: OnceLock<String> = OnceLock::new();

crates/pf-inject/src/lib.rs

@@ -457,6 +457,11 @@ pub mod triton_proto;
 #[cfg(target_os = "linux")]
 #[path = "inject/linux/triton_usbip.rs"]
 pub mod triton_usbip;
+/// Linux: the `/dev/uhid` event ABI shared by every UHID gamepad backend — the constants each
+/// used to transcribe for itself, plus the field accessors that read a payload's real length.
+#[cfg(target_os = "linux")]
+#[path = "inject/linux/uhid_abi.rs"]
+pub mod uhid_abi;
 /// The generic stateful virtual-pad manager ([`uhid_manager::UhidManager`]) — event routing, frame
 /// merge, heartbeat, and feedback pump shared by the five UHID/UMDF backends; each supplies only
 /// its per-controller protocol via [`uhid_manager::PadProto`] (G12).

crates/pf-paths/src/lib.rs

@@ -70,11 +70,64 @@ pub fn create_private_dir(dir: &std::path::Path) -> std::io::Result<()> {
     {
         let r = std::fs::create_dir_all(dir);
         #[cfg(windows)]
-        restrict_dir_to_system_admins(dir);
+        restrict_dir_to_system_admins(dir, first_hardening_of(dir));
         r
     }
 }
 
+/// Whether this is the first hardening pass of `dir` in this process — the pass that also does the
+/// expensive recursive re-own.
+///
+/// A planted config dir is planted once, before the host ever starts, so one deep pass at startup
+/// closes it; repeating it on every `create_private_dir` call (the library CRUD calls it per write)
+/// would re-walk the whole config tree — recordings, art cache — for nothing.
+#[cfg(windows)]
+fn first_hardening_of(dir: &std::path::Path) -> bool {
+    use std::collections::HashSet;
+    use std::sync::{Mutex, OnceLock};
+    static SEEN: OnceLock<Mutex<HashSet<PathBuf>>> = OnceLock::new();
+    SEEN.get_or_init(|| Mutex::new(HashSet::new()))
+        .lock()
+        .map(|mut s| s.insert(dir.to_path_buf()))
+        .unwrap_or(false)
+}
+
+/// Re-apply the secret-file DACL to a file that **already exists** — including re-owning it to
+/// Administrators.
+///
+/// [`write_secret_file`] hardens what it writes, but a file that was planted before the host first
+/// ran was never written by us: it is owned by whoever created it, and an owner always retains
+/// `WRITE_DAC`, so re-ACLing without re-owning leaves them able to put their access straight back.
+/// Used on startup for `host.env`, whose contents become the SYSTEM service's environment and
+/// command line (2026-08-05 review H-4). Best-effort and never fatal.
+#[cfg(windows)]
+pub fn restrict_existing_secret_file(path: &std::path::Path) {
+    if !path.exists() {
+        return;
+    }
+    let icacls = icacls_path();
+    let _ = std::process::Command::new(&icacls)
+        .arg(path.as_os_str())
+        .args(["/setowner", "*S-1-5-32-544"]) // BUILTIN\Administrators
+        .stdout(std::process::Stdio::null())
+        .stderr(std::process::Stdio::null())
+        .status();
+    restrict_to_system_admins(path);
+}
+
+/// No-op off Windows: POSIX modes are set at creation by [`write_secret_file`] and a config dir a
+/// non-root user pre-created is not a privilege boundary the way `%ProgramData%` is.
+#[cfg(not(windows))]
+pub fn restrict_existing_secret_file(_path: &std::path::Path) {}
+
+/// `icacls` by absolute path — a privileged service must never resolve it through `PATH`.
+#[cfg(windows)]
+fn icacls_path() -> String {
+    std::env::var("SystemRoot")
+        .map(|r| format!("{r}\\System32\\icacls.exe"))
+        .unwrap_or_else(|_| "icacls".to_string())
+}
+
 /// Best-effort Windows DACL lockdown of the config *directory* (the companion to
 /// [`restrict_to_system_admins`] for files). The default `%ProgramData%` ACL lets `BUILTIN\Users`
 /// create subfolders/files (and become `CREATOR OWNER`), so a non-admin could pre-create the
@@ -86,17 +139,23 @@ pub fn create_private_dir(dir: &std::path::Path) -> std::io::Result<()> {
 /// are additionally locked to SYSTEM/Admins by [`write_secret_file`]. Hard-coded SIDs
 /// (locale-independent) via the absolute `%SystemRoot%` path; never fatal.
 #[cfg(windows)]
-fn restrict_dir_to_system_admins(dir: &std::path::Path) {
-    let icacls = std::env::var("SystemRoot")
-        .map(|r| format!("{r}\\System32\\icacls.exe"))
-        .unwrap_or_else(|_| "icacls".to_string());
-    // Reset ownership of the directory object to Administrators first, so a dir a non-admin may have
-    // pre-created can't keep OWNER control (an owner can always rewrite the DACL). No `/T` — re-owning
-    // the dir itself is what defeats the pre-creation; recursing a large captures tree each call is
-    // needless churn (secret files are individually owner-locked by `write_secret_file`).
-    let _ = std::process::Command::new(&icacls)
-        .arg(dir.as_os_str())
-        .args(["/setowner", "*S-1-5-32-544"]) // BUILTIN\Administrators
+fn restrict_dir_to_system_admins(dir: &std::path::Path, deep: bool) {
+    let icacls = icacls_path();
+    // Reset ownership to Administrators first, so a dir a non-admin may have pre-created can't keep
+    // OWNER control (an owner always retains WRITE_DAC and can put its access straight back).
+    //
+    // `deep` (once per directory per process — see `first_hardening_of`) also re-owns the CONTENTS.
+    // Re-owning only the directory left every file the attacker had already created still owned by
+    // them, and therefore still theirs to rewrite, which is half of why the 2026-08-05 review's H-4
+    // was exploitable end to end. A planted tree is planted once, before the host first runs, so one
+    // deep pass at startup closes it without re-walking recordings and art cache on every write.
+    let mut own = std::process::Command::new(&icacls);
+    own.arg(dir.as_os_str())
+        .args(["/setowner", "*S-1-5-32-544"]); // BUILTIN\Administrators
+    if deep {
+        own.args(["/T", "/C", "/Q"]); // recurse, continue on error, quiet
+    }
+    let _ = own
         .stdout(std::process::Stdio::null())
         .stderr(std::process::Stdio::null())
         .status();
@@ -108,8 +167,13 @@ fn restrict_dir_to_system_admins(dir: &std::path::Path) {
             "*S-1-5-18:(OI)(CI)(F)", // NT AUTHORITY\SYSTEM
             "/grant:r",
             "*S-1-5-32-544:(OI)(CI)(F)", // BUILTIN\Administrators
-            "/grant:r",
-            "*S-1-3-4:(OI)(CI)(F)", // OWNER RIGHTS
+            // NO inheritable OWNER RIGHTS (`*S-1-3-4`) here, deliberately. It used to be granted
+            // `(OI)(CI)(F)`, which handed full control of every child object to whoever owned it —
+            // so a file a local user created before the hardening ran stayed writable by them even
+            // after the directory was re-owned (2026-08-05 review H-4, second half). SYSTEM and
+            // Administrators cover every account that legitimately writes here; a non-elevated
+            // manual run gets read-only config, which is the intended boundary rather than a
+            // regression — this directory drives command execution as SYSTEM.
             "/grant:r",
             "*S-1-5-32-545:(OI)(CI)(RX)", // BUILTIN\Users — read-only (no create/write → no plant)
         ])
@@ -130,6 +194,19 @@ fn restrict_dir_to_system_admins(dir: &std::path::Path) {
 /// Windows (the default `%ProgramData%` ACL is Users-readable). Mirrors the mgmt-token hardening; used
 /// for the host private key and the persisted trust stores so a local unprivileged user can neither
 /// read the key (impersonation) nor tamper with the paired allow-list (unauthorized pairing).
+///
+/// **Windows ordering caveat** (2026-08-05 review L-17): this is create-then-`icacls`, not
+/// create-with-DACL — `std::fs::OpenOptions` cannot pass a `SECURITY_ATTRIBUTES`, and this crate is
+/// `#![forbid(unsafe_code)]` so it cannot call `CreateFileW` itself. The file therefore exists
+/// briefly under its INHERITED ACL, and a failed `icacls` is a warning rather than an error.
+///
+/// What makes that acceptable is the DIRECTORY, and only the directory: every caller writes into
+/// the config dir, which [`create_private_dir`] now hardens unconditionally and BEFORE the first
+/// read of anything in it (review H-4/M-1), granting `BUILTIN\Users` read-only and no create. The
+/// inherited ACL a secret is born with is therefore already SYSTEM/Administrators-only, and the
+/// `icacls` below is defence in depth rather than the thing standing between a local user and the
+/// host key. Keep that ordering — if the directory hardening is ever moved back after a read, this
+/// window becomes real again.
 pub fn write_secret_file(path: &std::path::Path, contents: &[u8]) -> std::io::Result<()> {
     use std::io::Write;
     let mut opts = std::fs::OpenOptions::new();
@@ -160,9 +237,7 @@ pub fn write_secret_file(path: &std::path::Path, contents: &[u8]) -> std::io::Re
 /// `PATH`). Never fatal — on failure the file is simply left at the inherited ACL (today's behaviour).
 #[cfg(windows)]
 fn restrict_to_system_admins(path: &std::path::Path) {
-    let icacls = std::env::var("SystemRoot")
-        .map(|r| format!("{r}\\System32\\icacls.exe"))
-        .unwrap_or_else(|_| "icacls".to_string());
+    let icacls = icacls_path();
     let status = std::process::Command::new(icacls)
         .arg(path.as_os_str())
         .args([

crates/pf-presenter/src/present_pace.rs

@@ -30,6 +30,12 @@ const STALE_REOPEN_NS: u64 = 100_000_000;
 pub(crate) const MARGIN_STEP_NS: u64 = 500_000;
 pub(crate) const MARGIN_MAX_NS: u64 = 2_500_000;
 
+/// Judder (‰ of present intervals off the modal spacing) that on its own justifies a 1 Hz
+/// presenter line. A cadence defect produces no drops, no gate holds and healthy latency
+/// percentiles, so it would otherwise stay silent until someone set the debug env var.
+/// Occasional single-frame slips are normal; a twentieth of a window is not.
+pub(crate) const JUDDER_LOG_PERMILLE: u16 = 50;
+
 /// The decoded-frame store between the wake channel and the present call.
 ///
 /// `capacity == 0` = newest-wins (latency intent): `submit` replaces, `take` clears.
@@ -183,6 +189,15 @@ pub(crate) struct LatchClock {
     pending_count: u32,
     grid: punktfunk_core::phase::PanelGrid,
     fallback_period_ns: u64,
+    /// The cadence (judder) statistic — the only stat we publish that is not a latency,
+    /// and the only one that can see a pacing defect. Lives here because this is where
+    /// the on-glass stamps and the learned grid it quantises against already meet.
+    ///
+    /// ⚠ These stamps are `CLOCK_REALTIME` (the module's domain), so a wall-clock step
+    /// would forge one hitch that never happened. It lands in the stall/disordered
+    /// counters rather than the judder ratio, which is why that split is worth having.
+    /// Android feeds the metric a raw monotonic stamp and has no such exposure.
+    intervals: punktfunk_core::phase::PresentIntervals,
 }
 
 /// Spacings per handoff to [`punktfunk_core::phase::PanelGrid`]. Small enough that a real
@@ -198,14 +213,29 @@ impl LatchClock {
             pending_count: 0,
             grid: punktfunk_core::phase::PanelGrid::seeded(refresh_hz as i32),
             fallback_period_ns: 1_000_000_000 / u64::from(refresh_hz.max(1)),
+            intervals: punktfunk_core::phase::PresentIntervals::new(),
         }
     }
 
+    /// Drain the window's cadence summary — the 1 Hz stat boundary, beside the store and
+    /// gate counters.
+    pub(crate) fn take_cadence(&mut self) -> Option<punktfunk_core::phase::PresentCadence> {
+        self.intervals.take()
+    }
+
     /// Fold on-glass stamps (ascending). Spacings are measured against the previous
     /// stamp whatever the batching, so the loop's one-sample-per-pass drain still feeds
     /// the learner.
     pub(crate) fn note_batch(&mut self, stamps: &[u64]) {
+        // Seeded-or-learned, so cadence is scored from the first window rather than only
+        // once the learner has converged. Held for the batch: a mid-batch period change
+        // would requantise a handful of samples for no benefit.
+        let period_ns = self.period_ns() as i64;
         for &s in stamps {
+            // Cadence sees EVERY stamp, including the sub-millisecond pairs the grid
+            // learner skips below: two presents inside one refresh is not a grid step,
+            // but it is very much a cadence event (it scores as a zero-refresh interval).
+            self.intervals.record(s as i64, period_ns);
             if self.last_ns != 0 && s > self.last_ns {
                 let d = s - self.last_ns;
                 // < 1 ms apart = a queued pair, not a grid step.

crates/pf-presenter/src/run.rs

@@ -19,7 +19,8 @@
 use crate::input::{Capture, FingerPhase};
 use crate::overlay::{FrameCtx, Overlay, OverlayAction, OverlayFrame, SessionPhase};
 use crate::present_pace::{
-    Cadence, CadenceProbe, FrameStore, LatchClock, PresentGate, MARGIN_MAX_NS, MARGIN_STEP_NS,
+    Cadence, CadenceProbe, FrameStore, LatchClock, PresentGate, JUDDER_LOG_PERMILLE, MARGIN_MAX_NS,
+    MARGIN_STEP_NS,
 };
 use crate::touch::Abs;
 use crate::vk::{FrameInput, Presenter};
@@ -466,6 +467,13 @@ fn run_inner(mut opts: SessionOpts, mut mode: ModeCtl) -> Result<Option<Outcome>
     #[cfg(windows)]
     crate::win32::set_app_user_model_id();
     sdl3::hint::set("SDL_JOYSTICK_THREAD", "1");
+    // Hold SDL's Valve HIDAPI drivers off BEFORE SDL_Init: the Deck driver clears the pad's
+    // digital mappings at *enumeration*, which is part of bringing the gamepad subsystem up, so a
+    // hint set after `sdl.gamepad()` — where this used to live, inside GamepadService::pumped —
+    // only detached a driver that had already killed the built-in trackpad-mouse system-wide. The
+    // symptom was the Deck losing its trackpad cursor at the start of every session until the
+    // firmware watchdog restored lizard mode. They are still enabled for an attached session.
+    pf_client_core::gamepad::preinit_disable_valve_hidapi();
     // A touchscreen (the Deck's glass) is forwarded as REAL touch passthrough below — so
     // suppress SDL's default synthesis of mouse events from touch. Left on, every touch
     // ALSO warps a synthetic mouse to the touch point, which under the stream's relative
@@ -1814,6 +1822,7 @@ fn run_inner(mut opts: SessionOpts, mut mode: ModeCtl) -> Result<Option<Outcome>
                 // a second `take_counters` would read zeros.
                 let (replaced, q_drop, q_dry) = st.store.take_counters();
                 let (gated, forced) = st.gate.take_counters();
+                let cadence = st.clock.take_cadence();
                 st.presented = PresentedWindow {
                     e2e_p50_ms: e2e_p50 as f32 / 1000.0,
                     e2e_p95_ms: e2e_p95 as f32 / 1000.0,
@@ -1827,6 +1836,8 @@ fn run_inner(mut opts: SessionOpts, mut mode: ModeCtl) -> Result<Option<Outcome>
                     q_dry,
                     gated,
                     forced,
+                    judder_permille: cadence.map(|c| c.judder_permille).unwrap_or(0),
+                    cadence_mode: cadence.map(|c| c.mode_units).unwrap_or(0),
                 };
                 st.win_e2e_us.clear();
                 st.win_disp_us.clear();
@@ -1848,7 +1859,14 @@ fn run_inner(mut opts: SessionOpts, mut mode: ModeCtl) -> Result<Option<Outcome>
                 // The 1 Hz presenter line (the Apple `pf-present` analogue): emitted
                 // when anything moved, or always under PUNKTFUNK_PRESENT_DEBUG=1 —
                 // the field-triage instrument for the intent engine.
-                if pacing_active && (present_debug || q_drop + q_dry + gated + forced > 0) {
+                // Judder joins the "something moved" triggers deliberately: a cadence
+                // defect shows NO drops, NO gate holds and healthy percentiles, so
+                // without this a stream can judder visibly and never emit a line.
+                if pacing_active
+                    && (present_debug
+                        || q_drop + q_dry + gated + forced > 0
+                        || st.presented.judder_permille >= JUDDER_LOG_PERMILLE)
+                {
                     tracing::info!(
                         smoothing = st.presented.smoothing,
                         mode = st.presented.mode,
@@ -1864,6 +1882,8 @@ fn run_inner(mut opts: SessionOpts, mut mode: ModeCtl) -> Result<Option<Outcome>
                         latch_ms = st.presented.latch_ms,
                         period_us = st.clock.period_ns() / 1000,
                         margin_us = st.margin_ns / 1000,
+                        judder_permille = st.presented.judder_permille,
+                        cadence_mode = st.presented.cadence_mode,
                         "presenter window"
                     );
                 }
@@ -1895,6 +1915,13 @@ fn run_inner(mut opts: SessionOpts, mut mode: ModeCtl) -> Result<Option<Outcome>
         }
     };
 
+    // Every exit from the loop above converges here, which is why the gamepad teardown belongs
+    // here and not on the individual `break`s. `gamepad.detach()` only queues the detach; the
+    // close — flush, host-side GamepadRemove, and the explicit rumble-stop backstop — runs when
+    // the pump drains it. Single mode broke out of the loop immediately after detaching and
+    // Event::Quit never detached at all, so both left forwarded pads unflushed and, if the game
+    // was rumbling at the time, still buzzing.
+    pump.shutdown();
     // Join the pump BEFORE the device-wide idle: its decode submissions on the shared
     // device would race vkDeviceWaitIdle otherwise.
     if let Some(st) = stream.take() {
@@ -2354,6 +2381,14 @@ struct PresentedWindow {
     q_dry: u32,
     gated: u32,
     forced: u32,
+    /// The cadence (judder) statistic — the fraction of present intervals (‰) that missed
+    /// the modal spacing, and that modal spacing in whole refreshes. Every other number
+    /// here is a latency and none of them can see a pacing defect: alternating 1 and 3
+    /// refreshes has the same mean rate as a steady 2, better latency percentiles, and
+    /// looks broken. `mode 0` = not enough evidence this window.
+    /// See [`punktfunk_core::phase::PresentIntervals`].
+    judder_permille: u16,
+    cadence_mode: u8,
 }
 
 /// The capture hints (`ui_stream` parity — the words the user reads while released).

crates/pf-vdisplay/Cargo.toml

@@ -66,6 +66,11 @@ pf-driver-proto = { path = "../pf-driver-proto" }
 bytemuck = { version = "1.19", features = ["derive"] }
 windows = { version = "0.62", features = [
     "Win32_Foundation",
+    # The single-instance mutex is created with an explicit SDDL DACL and its owner is checked, so
+    # a lower-privileged process (the LocalService plugin runner) can neither open it nor squat the
+    # name unnoticed — see manager/instance.rs (security-review 2026-08-05 L-16).
+    "Win32_Security",
+    "Win32_Security_Authorization",
     "Win32_Devices_DeviceAndDriverInstallation",
     "Win32_Devices_Display",
     "Win32_Graphics_Gdi",

crates/pf-vdisplay/src/vdisplay/windows/manager.rs

@@ -1764,6 +1764,11 @@ impl VirtualDisplayManager {
             if let Some(saved) = inner.group.ccd_saved.take() {
                 restore_displays_ccd(&saved);
             }
+            // Drop the isolate's crash-recovery marker even when there was no snapshot to restore
+            // (a failed `isolate_displays_ccd` leaves `ccd_saved` None, and `restore_displays_ccd`
+            // — which clears it itself — then never runs). The group is gone either way, so no
+            // future host start owes this desk a force-EXTEND.
+            pf_win_display::win_display::isolate_journal::clear();
             // EXPERIMENTAL `ddc_power_off` wake. OUTSIDE the `ccd_saved` gate, for the same reason
             // `pnp_disabled` is above it: the panels were commanded dark BEFORE the isolate, and
             // the isolate can return `None` (its `query_active_config` failed). Nested inside that

crates/pf-vdisplay/src/vdisplay/windows/manager/instance.rs

@@ -3,6 +3,7 @@
 //! `IOCTL_CLEAR_ALL` and razing the live host's monitors mid-stream.
 
 use super::*;
+use windows::Win32::Security::{PSECURITY_DESCRIPTOR, SECURITY_ATTRIBUTES};
 
 /// The held single-instance mutex (`None` until claimed). Process-global — not per-manager — so the
 /// serve path can claim it EAGERLY at startup, before any session opens the backend: the claim is
@@ -40,16 +41,40 @@ fn acquire_single_instance() -> Result<OwnedHandle> {
          machine — refusing to touch the driver (a second manager's startup CLEAR_ALL would raze \
          the live host's monitors mid-stream). Stop the other instance (e.g. `punktfunk-host \
          service stop`) first.";
-    // SAFETY: plain FFI create of a named mutex; the returned handle (checked) is solely owned by
-    // the `OwnedHandle`, and `GetLastError` is read immediately after the create — the documented
-    // ERROR_ALREADY_EXISTS protocol for pre-existing named objects.
+    // A name in `Global\` is creatable by ANY principal holding SeCreateGlobalPrivilege — which
+    // includes the LocalService account the plugin runner is forced to (plugins.rs). With `None`
+    // security attributes this object took the DACL from the creating token's default, and a
+    // squatter who got there first (creating the name with a DACL that denies SYSTEM) permanently
+    // and silently disabled every virtual-display session: the host lands in the ACCESS_DENIED arm
+    // below and reports a perfectly reasonable "another instance is managing the driver", which
+    // sends the operator hunting a process that does not exist (2026-08-05 review L-16).
+    //
+    // Two changes: create with an EXPLICIT DACL so lesser principals cannot open ours, and check
+    // the OWNER of a name that already exists so a squat is reported as a squat.
+    let sd = security_descriptor()?;
+    let sa = SECURITY_ATTRIBUTES {
+        nLength: std::mem::size_of::<SECURITY_ATTRIBUTES>() as u32,
+        lpSecurityDescriptor: sd.0,
+        bInheritHandle: false.into(),
+    };
+    // SAFETY: plain FFI create of a named mutex; `sa` (and the descriptor it points at) outlives
+    // the call, the returned handle (checked) is solely owned by the `OwnedHandle`, and
+    // `GetLastError` is read immediately after the create — the documented ERROR_ALREADY_EXISTS
+    // protocol for pre-existing named objects.
     unsafe {
-        let h = match CreateMutexW(None, false, w!("Global\\punktfunk-vdisplay-manager")) {
+        let h = match CreateMutexW(Some(&sa), false, w!("Global\\punktfunk-vdisplay-manager")) {
             Ok(h) => h,
             // The name exists but its creator's DACL denies this token the implicit OPEN (the SCM
             // service creates it as SYSTEM; a second elevated-admin host lands here instead of in
-            // the ALREADY_EXISTS branch — validated on-glass). Same meaning: an instance is live.
-            Err(e) if e.code().0 == 0x8007_0005u32 as i32 => anyhow::bail!("{IN_USE}"),
+            // the ALREADY_EXISTS branch — validated on-glass). Legitimately that means an instance
+            // is live; it is ALSO exactly what a squat looks like, so say both.
+            Err(e) if e.code().0 == 0x8007_0005u32 as i32 => anyhow::bail!(
+                "{IN_USE}\n\nIf no other punktfunk-host is running, the name \
+                 `Global\\punktfunk-vdisplay-manager` has been SQUATTED by another process — any \
+                 account with SeCreateGlobalPrivilege can create it first and deny us access, \
+                 which disables virtual-display streaming until that process exits. Find the \
+                 holder with Sysinternals `handle.exe -a punktfunk-vdisplay-manager`."
+            ),
             Err(e) => {
                 return Err(e).context("CreateMutexW(punktfunk-vdisplay single-instance guard)");
             }
@@ -57,8 +82,114 @@ fn acquire_single_instance() -> Result<OwnedHandle> {
         let already = GetLastError() == ERROR_ALREADY_EXISTS;
         let owned = OwnedHandle::from_raw_handle(h.0 as _);
         if already {
+            // We opened an existing object — so its DACL let us in, but that says nothing about
+            // who created it. If the owner is not SYSTEM/Administrators it is not one of ours.
+            if let Some(owner) = object_owner_sid(h) {
+                if !is_privileged_sid(&owner) {
+                    anyhow::bail!(
+                        "the pf-vdisplay single-instance name is held by a NON-ADMINISTRATIVE \
+                         process (owner SID {owner}) — this is not another punktfunk-host, it is a \
+                         squat on `Global\\punktfunk-vdisplay-manager`, and it blocks all \
+                         virtual-display streaming while it is held."
+                    );
+                }
+            }
             anyhow::bail!("{IN_USE}");
         }
         Ok(owned)
     }
 }
+
+/// `D:P(A;;GA;;;SY)(A;;GA;;;BA)` — a protected DACL (no inheritance) granting Full to SYSTEM and
+/// BUILTIN\Administrators, and to nobody else. Everything that legitimately manages pf-vdisplay is
+/// one of those two; a LocalService plugin runner is neither, so it can no longer open our object.
+fn security_descriptor() -> Result<LocalSd> {
+    use windows::Win32::Security::Authorization::ConvertStringSecurityDescriptorToSecurityDescriptorW;
+    use windows::Win32::Security::Authorization::SDDL_REVISION_1;
+    let mut psd = PSECURITY_DESCRIPTOR::default();
+    // SAFETY: the SDDL literal is NUL-terminated (`w!`), and `psd` is a live out-param whose
+    // allocation is taken over by `LocalSd` below.
+    unsafe {
+        ConvertStringSecurityDescriptorToSecurityDescriptorW(
+            w!("D:P(A;;GA;;;SY)(A;;GA;;;BA)"),
+            SDDL_REVISION_1,
+            &mut psd,
+            None,
+        )
+    }
+    .context("build the pf-vdisplay single-instance security descriptor")?;
+    Ok(LocalSd(psd.0))
+}
+
+/// Owns a `LocalAlloc`'d security descriptor and frees it on drop.
+struct LocalSd(*mut core::ffi::c_void);
+
+impl Drop for LocalSd {
+    fn drop(&mut self) {
+        if !self.0.is_null() {
+            // SAFETY: the pointer came from ConvertStringSecurityDescriptorToSecurityDescriptorW,
+            // which documents LocalFree as the matching deallocation.
+            unsafe {
+                let _ = windows::Win32::Foundation::LocalFree(Some(
+                    windows::Win32::Foundation::HLOCAL(self.0),
+                ));
+            }
+            self.0 = std::ptr::null_mut();
+        }
+    }
+}
+
+/// The owner SID of a kernel object, as an SDDL string. `None` when it cannot be read (the handle
+/// lacks READ_CONTROL) — treated as "unknown", never as "fine".
+fn object_owner_sid(h: HANDLE) -> Option<String> {
+    use windows::Win32::Foundation::{LocalFree, HLOCAL};
+    use windows::Win32::Security::Authorization::{
+        ConvertSidToStringSidW, GetSecurityInfo, SE_KERNEL_OBJECT,
+    };
+    use windows::Win32::Security::{OWNER_SECURITY_INFORMATION, PSID};
+
+    let mut owner = PSID::default();
+    let mut sd = PSECURITY_DESCRIPTOR::default();
+    // SAFETY: `h` is the live mutex handle; the out-params are live locals; `sd` is the single
+    // allocation and is LocalFree'd below.
+    let rc = unsafe {
+        GetSecurityInfo(
+            h,
+            SE_KERNEL_OBJECT,
+            OWNER_SECURITY_INFORMATION,
+            Some(&mut owner),
+            None,
+            None,
+            None,
+            Some(&mut sd),
+        )
+    };
+    let out = if rc.is_ok() && !owner.is_invalid() {
+        let mut sid_str = windows::core::PWSTR::null();
+        // SAFETY: `owner` points into `sd` and is a valid SID; `sid_str` is a live out-param whose
+        // LocalAlloc'd string is freed immediately below.
+        unsafe {
+            if ConvertSidToStringSidW(owner, &mut sid_str).is_ok() && !sid_str.is_null() {
+                let text = sid_str.to_string().unwrap_or_default();
+                let _ = LocalFree(Some(HLOCAL(sid_str.0 as _)));
+                Some(text)
+            } else {
+                None
+            }
+        }
+    } else {
+        None
+    };
+    // SAFETY: `sd` is the LocalAlloc'd descriptor GetSecurityInfo returned (null when it failed,
+    // which LocalFree tolerates).
+    unsafe {
+        let _ = LocalFree(Some(HLOCAL(sd.0)));
+    }
+    out
+}
+
+/// SYSTEM, BUILTIN\Administrators, or a member of the Administrators-owned set — the principals a
+/// legitimate pf-vdisplay manager runs as.
+fn is_privileged_sid(sid: &str) -> bool {
+    matches!(sid, "S-1-5-18" | "S-1-5-32-544") || sid.starts_with("S-1-5-80-") // service SIDs
+}

crates/pf-win-display/src/win_display.rs

@@ -1215,6 +1215,186 @@ pub fn target_inventory() -> Vec<TargetInventory> {
     out
 }
 
+/// Crash-recovery journal for the EXCLUSIVE isolate — the marker that lets a *fresh* host undo what
+/// a *dead* one did.
+///
+/// [`isolate_displays_ccd`] deactivates the operator's physical displays and hands the pre-isolate
+/// topology back to its caller, which restores it at teardown ([`restore_displays_ccd`]). That
+/// snapshot lives in **process memory only**, so a host that crashes, is killed, or is stopped
+/// mid-session never restores it. Windows does not restore it either — the isolated topology is
+/// deliberately never saved to the CCD database, precisely so teardown can put the user's layout
+/// back. The result was a field-reported dead end: the physical screen stays dark, no timeout ever
+/// fires, and nothing in the product puts it back (the operator's only recourse was `DisplaySwitch`
+/// or a reboot).
+///
+/// Same shape as [`monitor_devnode`](crate::monitor_devnode)'s PnP journal: write a marker while the
+/// isolate is live, clear it on a clean restore, and re-light the desk at host startup if a marker
+/// survived.
+///
+/// **Why the EXTEND preset rather than replaying the saved CCD blob.** That blob pins target ids
+/// *including the virtual display's*, and the crashed host's monitors die with it (startup reaps the
+/// orphans), so a replay would mostly fail `ERROR_BAD_CONFIGURATION` and land in the very
+/// force-EXTEND backstop [`restore_displays_ccd`] already keeps for that case. EXTEND re-activates
+/// every connected display from the OS's own database, needs no struct serialization, and stays
+/// correct across a reboot — where saved target ids would be stale anyway.
+pub mod isolate_journal {
+    use std::sync::Mutex;
+
+    /// What we last wrote, so the exclusive re-assert watchdog's repeat isolates don't rewrite the
+    /// file every couple of seconds. `None` = "no marker known to be on disk".
+    static LAST: Mutex<Option<Vec<u32>>> = Mutex::new(None);
+
+    fn path() -> std::path::PathBuf {
+        pf_paths::config_dir().join("display-isolate-active.json")
+    }
+
+    /// Record that `deactivated` physical target(s) are switched off for a live exclusive isolate.
+    /// Best-effort: a journal we cannot write costs crash recovery, not the session.
+    pub fn mark(deactivated: &[u32]) {
+        if deactivated.is_empty() {
+            return; // nothing was deactivated ⇒ nothing for a later host to put back
+        }
+        let mut last = LAST.lock().unwrap_or_else(|e| e.into_inner());
+        if last.as_deref() == Some(deactivated) {
+            return;
+        }
+        let p = path();
+        if let Some(dir) = p.parent() {
+            let _ = pf_paths::create_private_dir(dir);
+        }
+        match std::fs::write(
+            &p,
+            serde_json::to_vec_pretty(deactivated).unwrap_or_default(),
+        ) {
+            Ok(()) => *last = Some(deactivated.to_vec()),
+            Err(e) => tracing::warn!(
+                error = %e,
+                "display isolate: could not write the crash-recovery journal — if this host dies \
+                 mid-session the deactivated panels will stay dark"
+            ),
+        }
+    }
+
+    /// The isolate is over (restored, or there was nothing to restore) — drop the marker.
+    /// Idempotent; safe to call when no marker exists.
+    pub fn clear() {
+        let mut last = LAST.lock().unwrap_or_else(|e| e.into_inner());
+        let _ = std::fs::remove_file(path());
+        *last = None;
+    }
+
+    /// Host-startup crash recovery: if a previous host exited with an exclusive isolate live, its
+    /// physical displays are still deactivated. Re-light them with the EXTEND preset.
+    ///
+    /// Call once, early in `serve`, **before** any session touches the topology. Gated on the marker
+    /// rather than on "is anything active", so a legitimately headless host is never forced awake.
+    pub fn startup_recover() {
+        let Some(targets) = pending() else {
+            return;
+        };
+        tracing::warn!(
+            deactivated = ?targets,
+            "display isolate: a previous host exited with the operator's display(s) deactivated for \
+             an EXCLUSIVE session and never restored them — forcing the EXTEND preset so the desk is \
+             not left dark"
+        );
+        super::force_extend_topology();
+        clear();
+    }
+
+    /// The marker a previous host left behind, if any (its deactivated target ids) — the *decision*
+    /// half of [`startup_recover`], split out so the recovery rule is testable without driving a
+    /// real `SetDisplayConfig` against the machine running the test.
+    pub fn pending() -> Option<Vec<u32>> {
+        let bytes = std::fs::read(path()).ok()?;
+        Some(serde_json::from_slice(&bytes).unwrap_or_default())
+    }
+
+    #[cfg(test)]
+    mod tests {
+        use super::*;
+
+        /// `PUNKTFUNK_CONFIG_DIR` (which `path()` resolves through) and the `LAST` cache are both
+        /// process-global, so these cases must not interleave.
+        static ENV: Mutex<()> = Mutex::new(());
+
+        /// Point the journal at a scratch dir for the duration of one case.
+        fn with_temp_dir(name: &str, f: impl FnOnce(&std::path::Path)) {
+            let _g = ENV.lock().unwrap_or_else(|e| e.into_inner());
+            let dir = std::env::temp_dir().join(format!("pf-isolate-journal-{name}"));
+            let _ = std::fs::remove_dir_all(&dir);
+            std::fs::create_dir_all(&dir).expect("scratch dir");
+            std::env::set_var("PUNKTFUNK_CONFIG_DIR", &dir);
+            clear(); // reset the LAST cache + any leftover marker from a previous run
+            f(&dir);
+            clear();
+            std::env::remove_var("PUNKTFUNK_CONFIG_DIR");
+            let _ = std::fs::remove_dir_all(&dir);
+        }
+
+        /// The crash path: a host marks what it switched off and dies. The next start must see the
+        /// marker (and which targets), which is what makes it force the desk back on.
+        #[test]
+        fn a_mark_survives_for_the_next_host_and_clear_retracts_it() {
+            with_temp_dir("roundtrip", |_| {
+                assert_eq!(pending(), None, "a clean box owes no recovery");
+                mark(&[101, 202]);
+                assert_eq!(
+                    pending(),
+                    Some(vec![101, 202]),
+                    "a crashed host's marker must be readable by the next start"
+                );
+                clear();
+                assert_eq!(pending(), None, "a clean teardown retracts the marker");
+            });
+        }
+
+        /// An isolate that deactivated nothing (single-display box: the virtual output is already
+        /// the only head) owes the next start no force-EXTEND — marking there would re-arrange a
+        /// desk we never touched.
+        #[test]
+        fn deactivating_nothing_writes_no_marker() {
+            with_temp_dir("empty", |_| {
+                mark(&[]);
+                assert_eq!(pending(), None);
+            });
+        }
+
+        /// The re-assert watchdog re-isolates every couple of seconds while something fights it;
+        /// that must not mean a disk write per cycle.
+        #[test]
+        fn repeating_the_same_mark_does_not_rewrite_the_file() {
+            with_temp_dir("cached", |dir| {
+                let file = dir.join("display-isolate-active.json");
+                mark(&[7]);
+                // Overwrite behind the journal's back rather than comparing mtimes — a filesystem
+                // whose timestamp resolution is coarser than two back-to-back writes would let an
+                // mtime assertion pass without proving anything.
+                std::fs::write(&file, b"SENTINEL").unwrap();
+                mark(&[7]);
+                assert_eq!(
+                    std::fs::read(&file).unwrap(),
+                    b"SENTINEL",
+                    "an unchanged mark must not rewrite the journal"
+                );
+                // A CHANGED set still lands — the group grew/shrank and recovery must follow it.
+                mark(&[7, 8]);
+                assert_eq!(pending(), Some(vec![7, 8]));
+            });
+        }
+
+        /// A corrupt/truncated journal must still trigger recovery: the FILE's existence is the
+        /// signal ("a host left displays off"), its contents are only diagnostics.
+        #[test]
+        fn an_unparseable_marker_still_asks_for_recovery() {
+            with_temp_dir("corrupt", |dir| {
+                std::fs::write(dir.join("display-isolate-active.json"), b"{ not json").unwrap();
+                assert_eq!(pending(), Some(Vec::new()));
+            });
+        }
+    }
+}
+
 /// Robust display isolation via the CCD API. The naive GDI approach (EnumDisplayDevices +
 /// ChangeDisplaySettings) MISSES displays on a hybrid box — an iGPU-attached physical monitor isn't
 /// flagged `ATTACHED_TO_DESKTOP` in the GDI enum, so it's never detached and the secure desktop /
@@ -1246,6 +1426,18 @@ pub fn isolate_displays_ccd(keep_target_ids: &[u32]) -> Option<SavedConfig> {
         return Some(saved);
     }
 
+    // Journal what we are about to switch off BEFORE the first apply, not after a verified one: the
+    // window this exists to cover includes dying mid-apply. `saved.0` is the ACTIVE path set
+    // (QDC_ONLY_ACTIVE_PATHS), so everything in it outside the keep set is exactly what teardown
+    // owes the operator back. See `isolate_journal`.
+    let doomed: Vec<u32> = saved
+        .0
+        .iter()
+        .map(|p| p.targetInfo.id)
+        .filter(|id| !keep_target_ids.contains(id))
+        .collect();
+    isolate_journal::mark(&doomed);
+
     // Deactivate every non-keep display, then VERIFY and RETRY. A field-reported bug had a physical
     // monitor STAY ACTIVE in exclusive mode, so we don't trust a single SetDisplayConfig: re-query the
     // live topology each attempt and re-apply until ONLY the keep set is active. Secure-desktop
@@ -1769,6 +1961,15 @@ static DARK_SINKS_FUTILE: std::sync::Mutex<Vec<(u32, String)>> = std::sync::Mute
 /// removed), re-activating the displays we deactivated.
 // pub so vdisplay::pf_vdisplay can reuse this backend-neutral CCD restore helper.
 pub fn restore_displays_ccd(saved: &SavedConfig) {
+    restore_displays_ccd_inner(saved);
+    // Clear the crash-recovery marker only AFTER the restore (and its dark-desk backstop) has run,
+    // never before: a host that dies part-way through the restore must still leave the marker
+    // behind so the next start re-lights the desk. `_inner` has several early returns, which is
+    // why this wraps rather than trailing the body.
+    isolate_journal::clear();
+}
+
+fn restore_displays_ccd_inner(saved: &SavedConfig) {
     let (paths, modes) = saved;
     if paths.is_empty() {
         return;

crates/punktfunk-core/cbindgen.toml

@@ -56,6 +56,167 @@ exclude = ["MsghdrX", "recvmsg_x", "mmsghdr", "sendmmsg", "recvmmsg"]
 "FRAME_MS" = "PUNKTFUNK_AUDIO_FRAME_MS"
 "SAMPLE_RATE_HZ" = "PUNKTFUNK_AUDIO_SAMPLE_RATE_HZ"
 
+# R21: every remaining exported constant, prefixed. cbindgen emits a bare `#define` per
+# `pub const`, so without an entry here names as generic as MAX_PADS, TAG_LEN, ABI_VERSION and
+# INPUT_MAGIC land in the namespace of every C embedder that includes this header — and, as the
+# note above says, a clashing #define silently takes the last definition rather than failing to
+# compile. The table above had been doing this by hand for the handful someone noticed; this is
+# the rest of them, so the stated rule finally holds for the whole surface.
+#
+# NOT covered, deliberately: associated constants (`ColorInfo_CP_BT709`, `ClockResync_ROUNDS`,
+# `ResyncGuard_MAX_REJECTED_STREAK`). cbindgen already qualifies those with their type name,
+# which is the very property whose absence makes a bare `MAX_PADS` dangerous — they are
+# namespaced, just not by us.
+"ABI_VERSION" = "PUNKTFUNK_ABI_VERSION"
+"APP_EXITED_CLOSE_CODE" = "PUNKTFUNK_APP_EXITED_CLOSE_CODE"
+"BTN_MISC1" = "PUNKTFUNK_BTN_MISC1"
+"BTN_PADDLE1" = "PUNKTFUNK_BTN_PADDLE1"
+"BTN_PADDLE2" = "PUNKTFUNK_BTN_PADDLE2"
+"BTN_PADDLE3" = "PUNKTFUNK_BTN_PADDLE3"
+"BTN_PADDLE4" = "PUNKTFUNK_BTN_PADDLE4"
+"CHROMA_IDC_420" = "PUNKTFUNK_CHROMA_IDC_420"
+"CHROMA_IDC_444" = "PUNKTFUNK_CHROMA_IDC_444"
+"CIPHER_AES_128_GCM" = "PUNKTFUNK_CIPHER_AES_128_GCM"
+"CIPHER_CHACHA20_POLY1305" = "PUNKTFUNK_CIPHER_CHACHA20_POLY1305"
+"CLIENT_CAP_AUDIO_RED" = "PUNKTFUNK_CLIENT_CAP_AUDIO_RED"
+"CLIENT_CAP_CURSOR" = "PUNKTFUNK_CLIENT_CAP_CURSOR"
+"CLIENT_CAP_PHASE_LOCK" = "PUNKTFUNK_CLIENT_CAP_PHASE_LOCK"
+"CLIP_CANCELLED_CODE" = "PUNKTFUNK_CLIP_CANCELLED_CODE"
+"CLIP_CHUNK" = "PUNKTFUNK_CLIP_CHUNK"
+"CLIP_FETCH_CAP" = "PUNKTFUNK_CLIP_FETCH_CAP"
+"CLIP_FETCH_DENIED" = "PUNKTFUNK_CLIP_FETCH_DENIED"
+"CLIP_FETCH_OK" = "PUNKTFUNK_CLIP_FETCH_OK"
+"CLIP_FETCH_STALE" = "PUNKTFUNK_CLIP_FETCH_STALE"
+"CLIP_FETCH_UNAVAILABLE" = "PUNKTFUNK_CLIP_FETCH_UNAVAILABLE"
+"CLIP_FILE_INDEX_NONE" = "PUNKTFUNK_CLIP_FILE_INDEX_NONE"
+"CLIP_FLAG_FILES" = "PUNKTFUNK_CLIP_FLAG_FILES"
+"CLIP_MAX_KINDS" = "PUNKTFUNK_CLIP_MAX_KINDS"
+"CLIP_MAX_MIME" = "PUNKTFUNK_CLIP_MAX_MIME"
+"CLIP_POLICY_FILES" = "PUNKTFUNK_CLIP_POLICY_FILES"
+"CLIP_POLICY_TEXT" = "PUNKTFUNK_CLIP_POLICY_TEXT"
+"CLIP_REASON_BACKEND_UNAVAILABLE" = "PUNKTFUNK_CLIP_REASON_BACKEND_UNAVAILABLE"
+"CLIP_REASON_NO_FILES" = "PUNKTFUNK_CLIP_REASON_NO_FILES"
+"CLIP_REASON_OK" = "PUNKTFUNK_CLIP_REASON_OK"
+"CLIP_REASON_POLICY_DISABLED" = "PUNKTFUNK_CLIP_REASON_POLICY_DISABLED"
+"CLIP_REASON_TAKEN_OVER" = "PUNKTFUNK_CLIP_REASON_TAKEN_OVER"
+"CLIP_STREAM_KIND_FETCH" = "PUNKTFUNK_CLIP_STREAM_KIND_FETCH"
+"ClockResync_ROUNDS" = "PUNKTFUNK_ClockResync_ROUNDS"
+"CODEC_AV1" = "PUNKTFUNK_CODEC_AV1"
+"CODEC_H264" = "PUNKTFUNK_CODEC_H264"
+"CODEC_HEVC" = "PUNKTFUNK_CODEC_HEVC"
+"CODEC_PYROWAVE" = "PUNKTFUNK_CODEC_PYROWAVE"
+"ColorInfo_CP_BT2020" = "PUNKTFUNK_ColorInfo_CP_BT2020"
+"ColorInfo_CP_BT709" = "PUNKTFUNK_ColorInfo_CP_BT709"
+"ColorInfo_MC_BT2020_NCL" = "PUNKTFUNK_ColorInfo_MC_BT2020_NCL"
+"ColorInfo_MC_BT709" = "PUNKTFUNK_ColorInfo_MC_BT709"
+"ColorInfo_TRC_BT709" = "PUNKTFUNK_ColorInfo_TRC_BT709"
+"ColorInfo_TRC_HLG" = "PUNKTFUNK_ColorInfo_TRC_HLG"
+"ColorInfo_TRC_PQ" = "PUNKTFUNK_ColorInfo_TRC_PQ"
+"CURSOR_RELATIVE_HINT" = "PUNKTFUNK_CURSOR_RELATIVE_HINT"
+"CURSOR_SHAPE_MAX_SIDE" = "PUNKTFUNK_CURSOR_SHAPE_MAX_SIDE"
+"CURSOR_STATE_MAGIC" = "PUNKTFUNK_CURSOR_STATE_MAGIC"
+"CURSOR_VISIBLE" = "PUNKTFUNK_CURSOR_VISIBLE"
+"FLAG_EOF" = "PUNKTFUNK_FLAG_EOF"
+"FLAG_PIC" = "PUNKTFUNK_FLAG_PIC"
+"FLAG_PROBE" = "PUNKTFUNK_FLAG_PROBE"
+"FLAG_SOF" = "PUNKTFUNK_FLAG_SOF"
+"HDR_META_BODY_LEN" = "PUNKTFUNK_HDR_META_BODY_LEN"
+"HDR_META_MAGIC" = "PUNKTFUNK_HDR_META_MAGIC"
+"HELLO_LAUNCH_MAX" = "PUNKTFUNK_HELLO_LAUNCH_MAX"
+"HELLO_NAME_MAX" = "PUNKTFUNK_HELLO_NAME_MAX"
+"HID_RAW_FEATURE" = "PUNKTFUNK_HID_RAW_FEATURE"
+"HID_RAW_OUTPUT" = "PUNKTFUNK_HID_RAW_OUTPUT"
+"HID_REPORT_MAX" = "PUNKTFUNK_HID_REPORT_MAX"
+"HIDOUT_MAGIC" = "PUNKTFUNK_HIDOUT_MAGIC"
+"HOST_CAP_AUDIO_RED" = "PUNKTFUNK_HOST_CAP_AUDIO_RED"
+"HOST_CAP_CLIPBOARD" = "PUNKTFUNK_HOST_CAP_CLIPBOARD"
+"HOST_CAP_CURSOR" = "PUNKTFUNK_HOST_CAP_CURSOR"
+"HOST_CAP_GAMEPAD_STATE" = "PUNKTFUNK_HOST_CAP_GAMEPAD_STATE"
+"HOST_CAP_PEN" = "PUNKTFUNK_HOST_CAP_PEN"
+"HOST_CAP_TEXT_INPUT" = "PUNKTFUNK_HOST_CAP_TEXT_INPUT"
+"HOST_TIMING_MAGIC" = "PUNKTFUNK_HOST_TIMING_MAGIC"
+"INBOUND_REQ_FLAG" = "PUNKTFUNK_INBOUND_REQ_FLAG"
+"INPUT_MAGIC" = "PUNKTFUNK_INPUT_MAGIC"
+"INPUT_WIRE_LEN" = "PUNKTFUNK_INPUT_WIRE_LEN"
+"LEGACY_STALE_MS" = "PUNKTFUNK_LEGACY_STALE_MS"
+"MAX_DATAGRAM_BYTES" = "PUNKTFUNK_MAX_DATAGRAM_BYTES"
+"MAX_PADS" = "PUNKTFUNK_MAX_PADS"
+"MAX_SCALE" = "PUNKTFUNK_MAX_SCALE"
+"MIC_MAGIC" = "PUNKTFUNK_MIC_MAGIC"
+"MIN_SCALE" = "PUNKTFUNK_MIN_SCALE"
+"MIN_SHARD_PAYLOAD" = "PUNKTFUNK_MIN_SHARD_PAYLOAD"
+"MIN_STREAM_BLOCK_SHARDS" = "PUNKTFUNK_MIN_STREAM_BLOCK_SHARDS"
+"MSG_BITRATE_CHANGED" = "PUNKTFUNK_MSG_BITRATE_CHANGED"
+"MSG_CLIP_CONTROL" = "PUNKTFUNK_MSG_CLIP_CONTROL"
+"MSG_CLIP_FETCH" = "PUNKTFUNK_MSG_CLIP_FETCH"
+"MSG_CLIP_FETCH_HDR" = "PUNKTFUNK_MSG_CLIP_FETCH_HDR"
+"MSG_CLIP_OFFER" = "PUNKTFUNK_MSG_CLIP_OFFER"
+"MSG_CLIP_STATE" = "PUNKTFUNK_MSG_CLIP_STATE"
+"MSG_CLOCK_ECHO" = "PUNKTFUNK_MSG_CLOCK_ECHO"
+"MSG_CLOCK_PROBE" = "PUNKTFUNK_MSG_CLOCK_PROBE"
+"MSG_CURSOR_RENDER" = "PUNKTFUNK_MSG_CURSOR_RENDER"
+"MSG_CURSOR_SHAPE" = "PUNKTFUNK_MSG_CURSOR_SHAPE"
+"MSG_LOSS_REPORT" = "PUNKTFUNK_MSG_LOSS_REPORT"
+"MSG_PAIR_CHALLENGE" = "PUNKTFUNK_MSG_PAIR_CHALLENGE"
+"MSG_PAIR_PROOF" = "PUNKTFUNK_MSG_PAIR_PROOF"
+"MSG_PAIR_REQUEST" = "PUNKTFUNK_MSG_PAIR_REQUEST"
+"MSG_PAIR_RESULT" = "PUNKTFUNK_MSG_PAIR_RESULT"
+"MSG_PHASE_REPORT" = "PUNKTFUNK_MSG_PHASE_REPORT"
+"MSG_PROBE_REQUEST" = "PUNKTFUNK_MSG_PROBE_REQUEST"
+"MSG_PROBE_RESULT" = "PUNKTFUNK_MSG_PROBE_RESULT"
+"MSG_RECONFIGURE" = "PUNKTFUNK_MSG_RECONFIGURE"
+"MSG_RECONFIGURED" = "PUNKTFUNK_MSG_RECONFIGURED"
+"MSG_REQUEST_KEYFRAME" = "PUNKTFUNK_MSG_REQUEST_KEYFRAME"
+"MSG_RFI_REQUEST" = "PUNKTFUNK_MSG_RFI_REQUEST"
+"MSG_SET_BITRATE" = "PUNKTFUNK_MSG_SET_BITRATE"
+"MSG_SHARD_PAYLOAD_ACK" = "PUNKTFUNK_MSG_SHARD_PAYLOAD_ACK"
+"MSG_SHARD_PAYLOAD_CHANGED" = "PUNKTFUNK_MSG_SHARD_PAYLOAD_CHANGED"
+"NO_OUTPUT_KEYFRAME_STREAK" = "PUNKTFUNK_NO_OUTPUT_KEYFRAME_STREAK"
+"PAIR_APPROVAL_TIMEOUT_CLOSE_CODE" = "PUNKTFUNK_PAIR_APPROVAL_TIMEOUT_CLOSE_CODE"
+"PAIR_BOUND_OTHER_CLOSE_CODE" = "PUNKTFUNK_PAIR_BOUND_OTHER_CLOSE_CODE"
+"PAIR_DENIED_CLOSE_CODE" = "PUNKTFUNK_PAIR_DENIED_CLOSE_CODE"
+"PAIR_NO_IDENTITY_CLOSE_CODE" = "PUNKTFUNK_PAIR_NO_IDENTITY_CLOSE_CODE"
+"PAIR_NOT_ARMED_CLOSE_CODE" = "PUNKTFUNK_PAIR_NOT_ARMED_CLOSE_CODE"
+"PAIR_RATE_LIMITED_CLOSE_CODE" = "PUNKTFUNK_PAIR_RATE_LIMITED_CLOSE_CODE"
+"PAIR_SUPERSEDED_CLOSE_CODE" = "PUNKTFUNK_PAIR_SUPERSEDED_CLOSE_CODE"
+"PEN_ANGLE_UNKNOWN" = "PUNKTFUNK_PEN_ANGLE_UNKNOWN"
+"PEN_BARREL1" = "PUNKTFUNK_PEN_BARREL1"
+"PEN_BARREL2" = "PUNKTFUNK_PEN_BARREL2"
+"PEN_BATCH_MAX" = "PUNKTFUNK_PEN_BATCH_MAX"
+"PEN_DISTANCE_UNKNOWN" = "PUNKTFUNK_PEN_DISTANCE_UNKNOWN"
+"PEN_IN_RANGE" = "PUNKTFUNK_PEN_IN_RANGE"
+"PEN_PREDICTED" = "PUNKTFUNK_PEN_PREDICTED"
+"PEN_SAMPLE_WIRE_LEN" = "PUNKTFUNK_PEN_SAMPLE_WIRE_LEN"
+"PEN_TILT_UNKNOWN" = "PUNKTFUNK_PEN_TILT_UNKNOWN"
+"PEN_TOUCH_TIMEOUT_MS" = "PUNKTFUNK_PEN_TOUCH_TIMEOUT_MS"
+"PEN_TOUCHING" = "PUNKTFUNK_PEN_TOUCHING"
+"PRESETS" = "PUNKTFUNK_PRESETS"
+"QUIT_CLOSE_CODE" = "PUNKTFUNK_QUIT_CLOSE_CODE"
+"REANCHOR_MARKS_TO_LIFT" = "PUNKTFUNK_REANCHOR_MARKS_TO_LIFT"
+"REJECT_BUSY_CLOSE_CODE" = "PUNKTFUNK_REJECT_BUSY_CLOSE_CODE"
+"ResyncGuard_MAX_REJECTED_STREAK" = "PUNKTFUNK_ResyncGuard_MAX_REJECTED_STREAK"
+"RFI_MAX_RANGE" = "PUNKTFUNK_RFI_MAX_RANGE"
+"RICH_INPUT_MAGIC" = "PUNKTFUNK_RICH_INPUT_MAGIC"
+"RUMBLE_V1_LEN" = "PUNKTFUNK_RUMBLE_V1_LEN"
+"RUMBLE_V2_LEN" = "PUNKTFUNK_RUMBLE_V2_LEN"
+"SETUP_FAILED_CLOSE_CODE" = "PUNKTFUNK_SETUP_FAILED_CLOSE_CODE"
+"TAG_LEN" = "PUNKTFUNK_TAG_LEN"
+"TRIGGER_EFFECT_MAX" = "PUNKTFUNK_TRIGGER_EFFECT_MAX"
+"USER_FLAG_CHUNK_ALIGNED" = "PUNKTFUNK_USER_FLAG_CHUNK_ALIGNED"
+"USER_FLAG_RECOVERY_ANCHOR" = "PUNKTFUNK_USER_FLAG_RECOVERY_ANCHOR"
+"USER_FLAG_RECOVERY_POINT" = "PUNKTFUNK_USER_FLAG_RECOVERY_POINT"
+"USER_FLAG_SLICE_STREAM" = "PUNKTFUNK_USER_FLAG_SLICE_STREAM"
+"VIDEO_CAP_10BIT" = "PUNKTFUNK_VIDEO_CAP_10BIT"
+"VIDEO_CAP_444" = "PUNKTFUNK_VIDEO_CAP_444"
+"VIDEO_CAP_CHACHA20" = "PUNKTFUNK_VIDEO_CAP_CHACHA20"
+"VIDEO_CAP_HDR" = "PUNKTFUNK_VIDEO_CAP_HDR"
+"VIDEO_CAP_HOST_TIMING" = "PUNKTFUNK_VIDEO_CAP_HOST_TIMING"
+"VIDEO_CAP_MULTI_SLICE" = "PUNKTFUNK_VIDEO_CAP_MULTI_SLICE"
+"VIDEO_CAP_PROBE_SEQ" = "PUNKTFUNK_VIDEO_CAP_PROBE_SEQ"
+"VIDEO_CAP_STREAMED_AU" = "PUNKTFUNK_VIDEO_CAP_STREAMED_AU"
+"WIRE_VERSION" = "PUNKTFUNK_WIRE_VERSION"
+"WIRE_VERSION_CLOSE_CODE" = "PUNKTFUNK_WIRE_VERSION_CLOSE_CODE"
+
 # QualifiedScreamingSnakeCase already qualifies each variant with the enum name
 # (PunktfunkStatus::Ok -> PUNKTFUNK_STATUS_OK); do NOT also set prefix_with_name or it doubles.
 [enum]

crates/punktfunk-core/src/abi.rs

@@ -670,6 +670,12 @@ pub const PUNKTFUNK_HIDOUT_TRIGGER: u8 = 3;
 /// side (0 = right pad, 1 = left pad); `effect[0..6]` packs `amplitude` / `period` / `count` as
 /// little-endian `u16`s with `effect_len = 6`. Clients without trackpad coils drop it.
 pub const PUNKTFUNK_HIDOUT_TRACKPAD_HAPTIC: u8 = 4;
+/// `PunktfunkHidOutput::kind` — the audio-control region of a DS5 output report (pad-audio
+/// routing/volumes; the audio SAMPLES arrive via [`punktfunk_connection_next_pad_audio`]).
+/// `which` = the condensed audio flags (bit0 = haptics-select, bits1..4 = the report's
+/// audio-valid flags); `effect[0..6]` = bytes 5..=10 of the report verbatim
+/// (headphone/speaker/mic volumes + routing) with `effect_len = 6`. Forwarded change-only.
+pub const PUNKTFUNK_HIDOUT_AUDIO_CTL: u8 = 5;
 /// Capacity of `PunktfunkHidOutput::effect` (the DualSense trigger parameter block).
 pub const PUNKTFUNK_HID_EFFECT_MAX: u8 = 11;
 
@@ -698,7 +704,10 @@ pub struct PunktfunkHidOutput {
     /// Trigger: number of valid bytes in `effect` (≤ `PUNKTFUNK_HID_EFFECT_MAX`).
     pub effect_len: u8,
     /// Trigger: the raw DualSense trigger parameter block (mode + params).
-    pub effect: [u8; 11],
+    /// Sized off [`PUNKTFUNK_HID_EFFECT_MAX`] rather than a second literal `11` — the constant is
+    /// exported precisely so embedders can size their own buffers against it, and it declaring one
+    /// number while the struct it describes hardcoded another was the whole hazard.
+    pub effect: [u8; PUNKTFUNK_HID_EFFECT_MAX as usize],
 }
 
 #[cfg(feature = "quic")]
@@ -759,6 +768,17 @@ impl PunktfunkHidOutput {
                 out.effect_len = 6;
             }
             HidOutput::HidRaw { .. } => return None,
+            HidOutput::AudioCtl { pad, flags, raw } => {
+                // Same packing idiom as TrackpadHaptic: `which` carries the flags byte,
+                // `effect[0..6]` the raw audio region. The u16 wire pad narrows losslessly
+                // because `HidOutput::decode` refuses one at or above `input::MAX_PADS` (B27) —
+                // it is enforced there, not merely assumed here.
+                out.kind = PUNKTFUNK_HIDOUT_AUDIO_CTL;
+                out.pad = *pad as u8;
+                out.which = *flags;
+                out.effect[0..6].copy_from_slice(raw);
+                out.effect_len = 6;
+            }
         }
         Some(out)
     }
@@ -1172,6 +1192,25 @@ pub const PUNKTFUNK_HOST_CAP_CLIPBOARD: u8 = 0x02;
 /// the client keeps its pen-as-touch fallback. (Mirrors `quic::HOST_CAP_PEN`;
 /// design/pen-tablet-input.md.)
 pub const PUNKTFUNK_HOST_CAP_PEN: u8 = 0x10;
+/// Host-capability bit in [`punktfunk_connection_host_caps`]: the host can capture per-gamepad
+/// audio (DualSense voice-coil haptics + speaker) and emit it on the 0xD1 plane toward pads
+/// declared capable via [`punktfunk_connection_set_pad_audio_caps`]. Set only when the client
+/// asked via [`PUNKTFUNK_CLIENT_CAP_PAD_AUDIO`]. (Mirrors `quic::HOST_CAP_PAD_AUDIO`.)
+pub const PUNKTFUNK_HOST_CAP_PAD_AUDIO: u8 = 0x40;
+
+/// Pad-audio `kind` ([`punktfunk_connection_next_pad_audio`]): the BACK channel pair — DualSense
+/// voice-coil haptics, 5 ms Opus frames. (Mirrors `quic::PAD_AUDIO_KIND_HAPTICS`.)
+pub const PUNKTFUNK_PAD_AUDIO_KIND_HAPTICS: u8 = 0;
+/// Pad-audio `kind`: the FRONT channel pair — the controller's built-in speaker, 10 ms Opus
+/// frames. (Mirrors `quic::PAD_AUDIO_KIND_SPEAKER`.)
+pub const PUNKTFUNK_PAD_AUDIO_KIND_SPEAKER: u8 = 1;
+
+/// [`punktfunk_connection_set_pad_audio_caps`] `audio_caps` bit: the pad renders the HAPTICS
+/// stream (a real DualSense's voice coils).
+pub const PUNKTFUNK_PAD_AUDIO_CAP_HAPTICS: u8 = 0x01;
+/// [`punktfunk_connection_set_pad_audio_caps`] `audio_caps` bit: the pad renders the SPEAKER
+/// stream.
+pub const PUNKTFUNK_PAD_AUDIO_CAP_SPEAKER: u8 = 0x02;
 
 // Keep the ABI cap bits in lockstep with the wire constants (compile-time guard against drift).
 #[cfg(feature = "quic")]
@@ -1186,6 +1225,20 @@ const _: () = {
     assert!(PUNKTFUNK_HOST_CAP_GAMEPAD_STATE == crate::quic::HOST_CAP_GAMEPAD_STATE);
     assert!(PUNKTFUNK_HOST_CAP_CLIPBOARD == crate::quic::HOST_CAP_CLIPBOARD);
     assert!(PUNKTFUNK_HOST_CAP_PEN == crate::quic::HOST_CAP_PEN);
+    assert!(PUNKTFUNK_HOST_CAP_PAD_AUDIO == crate::quic::HOST_CAP_PAD_AUDIO);
+    assert!(PUNKTFUNK_CLIENT_CAP_PAD_AUDIO == crate::quic::CLIENT_CAP_PAD_AUDIO);
+    assert!(PUNKTFUNK_PAD_AUDIO_KIND_HAPTICS == crate::quic::PAD_AUDIO_KIND_HAPTICS);
+    assert!(PUNKTFUNK_PAD_AUDIO_KIND_SPEAKER == crate::quic::PAD_AUDIO_KIND_SPEAKER);
+    // The setter's caps bits are the arrival flags bits 8/9 shifted down (the wire packing
+    // `input::encode_gamepad_arrival` applies).
+    assert!(
+        (PUNKTFUNK_PAD_AUDIO_CAP_HAPTICS as u32) << 8
+            == crate::input::ARRIVAL_FLAG_PAD_AUDIO_HAPTICS
+    );
+    assert!(
+        (PUNKTFUNK_PAD_AUDIO_CAP_SPEAKER as u32) << 8
+            == crate::input::ARRIVAL_FLAG_PAD_AUDIO_SPEAKER
+    );
     assert!(PUNKTFUNK_PEN_IN_RANGE == crate::quic::PEN_IN_RANGE);
     assert!(PUNKTFUNK_PEN_TOUCHING == crate::quic::PEN_TOUCHING);
     assert!(PUNKTFUNK_PEN_BARREL1 == crate::quic::PEN_BARREL1);
@@ -1768,6 +1821,13 @@ pub const PUNKTFUNK_CLIENT_CAP_CURSOR: u8 = 0x01;
 /// forward-compatible.
 pub const PUNKTFUNK_CLIENT_CAP_PHASE_LOCK: u8 = 0x02;
 
+/// [`punktfunk_connect_ex9`] `client_caps` bit: the client understands the pad-audio plane
+/// (0xD1 — per-gamepad DualSense voice-coil haptics + speaker). The embedder MUST then drain
+/// [`punktfunk_connection_next_pad_audio`] and declare each capable pad via
+/// [`punktfunk_connection_set_pad_audio_caps`]; the host emits pad audio only when it answers
+/// with [`PUNKTFUNK_HOST_CAP_PAD_AUDIO`]. (Mirrors `quic::CLIENT_CAP_PAD_AUDIO`.)
+pub const PUNKTFUNK_CLIENT_CAP_PAD_AUDIO: u8 = 0x08;
+
 /// Shared body of [`punktfunk_connect_ex7`] / [`punktfunk_connect_ex8`]: `status_out`
 /// (nullable) is written on EVERY path — `Ok`, the mapped [`PunktfunkError`],
 /// `InvalidArg` for bad arguments, `Panic` if the connect panicked.
@@ -2312,6 +2372,117 @@ pub unsafe extern "C" fn punktfunk_connection_next_audio_pcm(
     })
 }
 
+/// Pull the next pad-audio frame (0xD1) — one Opus frame of DualSense voice-coil haptics
+/// (`kind` = [`PUNKTFUNK_PAD_AUDIO_KIND_HAPTICS`], 5 ms) or built-in-speaker audio
+/// ([`PUNKTFUNK_PAD_AUDIO_KIND_SPEAKER`], 10 ms) for gamepad `*out_pad` — waiting up to
+/// `timeout_ms`. The payload is COPIED into `buf` (no borrow-until-next-call slot); the return
+/// value is its length in bytes, `0` = nothing this poll (timeout — or a DTX/oversized frame,
+/// both of which an embedder treats the same way), `-1` = the session ended (or an invalid
+/// handle/buffer). All pads/kinds share one queue — fan out by `*out_pad`/`*out_kind` to
+/// per-actuator Opus decoders. A frame larger than `buf_len` is dropped like the timeout case
+/// (the plane is lossy by design; any real Opus frame fits a 1500-byte buffer). Only a session
+/// connected with [`PUNKTFUNK_CLIENT_CAP_PAD_AUDIO`] against a
+/// [`PUNKTFUNK_HOST_CAP_PAD_AUDIO`] host — with the pad declared via
+/// [`punktfunk_connection_set_pad_audio_caps`] — ever receives any. Drain from a dedicated
+/// thread (one puller, may run alongside the other planes' pullers).
+///
+/// # Safety
+/// `c` is a valid connection handle; the `out_*` pointers are writable (NULLs are skipped);
+/// `buf` is writable for `buf_len` bytes.
+#[cfg(feature = "quic")]
+#[no_mangle]
+pub unsafe extern "C" fn punktfunk_connection_next_pad_audio(
+    c: *mut PunktfunkConnection,
+    out_pad: *mut u8,
+    out_kind: *mut u8,
+    out_seq: *mut u32,
+    out_pts_ns: *mut u64,
+    buf: *mut u8,
+    buf_len: usize,
+    timeout_ms: u32,
+) -> i32 {
+    let r = std::panic::catch_unwind(AssertUnwindSafe(|| {
+        // SAFETY: per the ABI contract - an opaque handle from a `*_new`/`*_pair` that the caller
+        // has not yet freed, or null, which `as_mut`/`as_ref` reports as `None` and the `match`
+        // here handles.
+        let c = match unsafe { c.as_ref() } {
+            Some(c) => c,
+            None => return -1,
+        };
+        if buf.is_null() && buf_len != 0 {
+            return -1;
+        }
+        match c
+            .inner
+            .next_pad_audio(std::time::Duration::from_millis(timeout_ms as u64))
+        {
+            Some(f) => {
+                if f.opus.is_empty() || f.opus.len() > buf_len {
+                    // DTX silence (skipped like the audio-PCM path — decoding an empty payload
+                    // as loss would synthesize concealment) or doesn't fit — report "nothing
+                    // this poll" (the next_hidout HidRaw-skip precedent; truncated Opus would
+                    // be undecodable anyway).
+                    return 0;
+                }
+                // SAFETY: per the ABI contract - each out-param below is OPTIONAL, so it is null-
+                // checked before it is written; `buf` is a caller-owned writable region of
+                // `buf_len` bytes and the copy length was just bounds-checked against it.
+                unsafe {
+                    if !out_pad.is_null() {
+                        *out_pad = f.pad;
+                    }
+                    if !out_kind.is_null() {
+                        *out_kind = f.kind;
+                    }
+                    if !out_seq.is_null() {
+                        *out_seq = f.seq;
+                    }
+                    if !out_pts_ns.is_null() {
+                        *out_pts_ns = f.pts_ns;
+                    }
+                    std::ptr::copy_nonoverlapping(f.opus.as_ptr(), buf, f.opus.len());
+                }
+                f.opus.len() as i32
+            }
+            // `None` folds timeout and closed; the shutdown flag tells them apart so the
+            // embedder's plane loop can exit instead of polling a dead session forever.
+            None if c.inner.is_session_ended() => -1,
+            None => 0,
+        }
+    }));
+    r.unwrap_or(-1)
+}
+
+/// Declare wire pad `pad`'s pad-audio render capabilities (`audio_caps`: OR of
+/// [`PUNKTFUNK_PAD_AUDIO_CAP_HAPTICS`] / [`PUNKTFUNK_PAD_AUDIO_CAP_SPEAKER`]) — how a client
+/// tells the host WHICH pads can actually play the 0xD1 streams. Call at controller attach,
+/// BEFORE the pad's arrival event is sent (the [`punktfunk_connection_set_rumble_quirks`]
+/// timing): the core folds the bits into the arrival's flags (bits 8/9), and only toward a
+/// [`PUNKTFUNK_HOST_CAP_PAD_AUDIO`] host — never calling this leaves the wire bytes exactly as
+/// before. Latest-wins per pad; unknown bits are masked off.
+///
+/// # Safety
+/// `c` is a valid connection handle. Callable from any thread.
+#[cfg(feature = "quic")]
+#[no_mangle]
+pub unsafe extern "C" fn punktfunk_connection_set_pad_audio_caps(
+    c: *mut PunktfunkConnection,
+    pad: u8,
+    audio_caps: u8,
+) -> PunktfunkStatus {
+    guard(|| {
+        // SAFETY: per the ABI contract - an opaque handle from a `*_new`/`*_pair` that the caller
+        // has not yet freed, or null, which `as_mut`/`as_ref` reports as `None` and the `match`
+        // here handles.
+        let c = match unsafe { c.as_ref() } {
+            Some(c) => c,
+            None => return PunktfunkStatus::NullPointer,
+        };
+        c.inner.set_pad_audio_caps(pad, audio_caps);
+        PunktfunkStatus::Ok
+    })
+}
+
 /// Pull the next rumble (force-feedback) update, waiting up to `timeout_ms`. Amplitudes
 /// are 0..0xFFFF (`low` = low-frequency motor, `high` = high-frequency), `(0, 0)` = stop.
 /// Same timeout/closed semantics as [`punktfunk_connection_next_audio`].
@@ -2497,10 +2668,12 @@ pub unsafe extern "C" fn punktfunk_connection_next_rumble_cmd(
 /// Declare a physical actuator's quirks for wire pad `pad` — how a platform parameterizes the
 /// shared rumble policy engine instead of forking it (typically called at controller attach).
 /// `keepalive_ms`: re-emit an unchanged non-zero level at this cadence for actuators whose
-/// hardware output decays between wire renewals (Steam Deck ≈ 40, DualSense-over-BT raw HID
-/// ≈ 900); `0` = none. `min_pulse_ms`: floor for `backstop_ms` on non-zero commands. `flags`:
+/// hardware output decays between wire renewals (the Steam Deck's ≈ 40 is the one in-tree user);
+/// `0` = none. `min_pulse_ms`: floor for `backstop_ms` on non-zero commands — no in-tree caller
+/// sets it, it exists for embedders whose duration-taking API rejects short values. `flags`:
 /// [`PUNKTFUNK_RUMBLE_QUIRK_DEDUP_JITTER`]. All-zero (the initial state) describes a well-behaved
-/// actuator.
+/// actuator. See [`ActuatorQuirks`](crate::client::rumble::ActuatorQuirks) for why a renderer that
+/// dedupes its own writes (the Apple HID path) cannot use `keepalive_ms` and keeps its own.
 ///
 /// # Safety
 /// `c` is a valid connection handle. Callable from any thread.
@@ -4412,3 +4585,36 @@ pub unsafe extern "C" fn punktfunk_reanchor_gate_is_holding(
         PunktfunkStatus::Ok
     })
 }
+
+#[cfg(all(test, feature = "quic"))]
+mod tests {
+    use super::*;
+
+    /// The `AudioCtl` → `PunktfunkHidOutput` mapping: kind 5, pad narrowed, `which` carries the
+    /// flags byte, `effect[0..6]` the raw audio region with `effect_len = 6` (the TrackpadHaptic
+    /// packing idiom — no struct growth, so the size guard above stays at 19).
+    #[test]
+    fn hidout_abi_maps_audio_ctl() {
+        let out = PunktfunkHidOutput::from_hid(&crate::quic::HidOutput::AudioCtl {
+            pad: 3,
+            flags: 0x17,
+            raw: [0x50, 0x60, 0x70, 0x05, 0, 0],
+        })
+        .unwrap();
+        assert_eq!(out.kind, PUNKTFUNK_HIDOUT_AUDIO_CTL);
+        assert_eq!(out.pad, 3);
+        assert_eq!(out.which, 0x17);
+        assert_eq!(out.effect_len, 6);
+        assert_eq!(out.effect[..6], [0x50, 0x60, 0x70, 0x05, 0, 0]);
+        assert_eq!(out.effect[6..], [0; 5]);
+        // A raw passthrough report still has no C representation (skipped at the pull site).
+        assert!(
+            PunktfunkHidOutput::from_hid(&crate::quic::HidOutput::HidRaw {
+                pad: 0,
+                kind: 0,
+                data: vec![0x80],
+            })
+            .is_none()
+        );
+    }
+}

crates/punktfunk-core/src/abr.rs

@@ -159,6 +159,17 @@ const CAP_REPROBE_WINDOWS_MAX: u32 = 128;
 /// choke again at the same place, and only backoffs at a climbed-to rate can agree within the
 /// band (a cascade's second backoff sits at ×0.7 of the first: outside it by construction).
 const DECODE_CAP_SIMILAR_DIV: u32 = 8;
+/// A deciding window that DELIVERED under `current / STARVED_DELIVERY_DIV` is STARVED: the
+/// stream barely flowed (a host-side capture stall, an outage, a mid-window pause), so whatever
+/// distress the window carries — a flush, a keyframe-ask burst — is starvation-shaped, not
+/// rate-shaped, and the decoder decoded almost nothing at the nominal rate. Such a window may
+/// still back off (real damage deserves the safe response) but must never be a decode-knee
+/// sample: latching `current_kbps` off a starved window teaches a phantom decoder cap at
+/// whatever rate the stall interrupted (the periodic-capture-stall field case: every 5 s cycle
+/// offers another pair of "backoffs" at the same rate — a bogus latch that then fights the
+/// re-probe ladder for minutes). Deliberately far below the ×¾ utilization bar climbs require:
+/// the band between them is ambiguous and keeps today's behavior.
+const STARVED_DELIVERY_DIV: u32 = 4;
 /// Rolling window (in 750 ms report windows, ~30 s) whose minimum mean is the OWD baseline.
 /// Long enough to remember the uncongested floor, short enough to follow genuine path changes.
 const BASELINE_WINDOWS: usize = 40;
@@ -697,6 +708,10 @@ impl BitrateController {
                 || self.streak_decode_windows >= BAD_WINDOWS_TO_DECREASE
                 || (recovery_kf >= RECOVERY_KF_BAD && loss_ppm < HEAVY_LOSS_PPM)
                 || (flushed && (decode_bad || decode_mean_us.is_none()));
+            // Starved deciding window (see [`STARVED_DELIVERY_DIV`]): the stream barely flowed,
+            // so the window says nothing about what the decoder can hold at this rate.
+            let starved =
+                (actual_kbps as u64) * (STARVED_DELIVERY_DIV as u64) < self.current_kbps as u64;
             if !self.climb_since_backoff {
                 // Still draining the previous backoff: the host acks a ×0.7 request in ~100 ms,
                 // so this window's rate is one the decoder never choked at while keeping up —
@@ -708,6 +723,17 @@ impl BitrateController {
                     "adaptive bitrate: backoff without an intervening climb — draining the \
                      previous choke, not a knee sample"
                 );
+            } else if starved {
+                // Same "not a knee sample either way" treatment as the draining arm: neither
+                // latch against a starved window nor let it erase the reference a real knee
+                // set — the next genuine choke at that rate must still find its pair.
+                tracing::debug!(
+                    at_kbps = self.current_kbps,
+                    actual_kbps,
+                    reference_kbps = self.decode_backoff_kbps,
+                    "adaptive bitrate: backoff in a starved window (delivery a fraction of \
+                     the target) — starvation-shaped distress, not a knee sample"
+                );
             } else if decode_evidence {
                 let rate = self.current_kbps;
                 let similar = self.decode_backoff_kbps > 0
@@ -2084,6 +2110,100 @@ mod tests {
         rate - rate / 16
     }
 
+    /// One capture-stall-shaped window at the current rate: almost nothing delivered
+    /// (current/10), nothing decoded, no loss — but a jump-to-live flush and a keyframe-ask
+    /// storm (the stall edge's damage signature). SEVERE, so it backs off; STARVED, so it must
+    /// never be a knee sample.
+    fn stall_choke(c: &mut BitrateController, start: Instant, tick: &mut u32) -> Option<u32> {
+        *tick += 2;
+        let r = c.on_window(
+            ticks(start, *tick),
+            0,
+            0,
+            None,
+            None,
+            None,
+            c.current_kbps / 10,
+            true,
+            RECOVERY_KF_SEVERE,
+        );
+        *tick += 1;
+        r
+    }
+
+    #[test]
+    fn capture_stall_windows_never_latch_a_decode_cap() {
+        // The periodic-capture-stall field case (RDNA4 standby-sink, 5 s cycle): every stall
+        // edge offers another flush + kf-storm "backoff" at the SAME rate — without the starved
+        // guard that pair latches a phantom decoder knee at whatever rate the display driver
+        // happened to interrupt, and the session then fights the re-probe ladder for minutes.
+        let mut c = BitrateController::new(240_000);
+        c.set_ceiling(900_000);
+        let start = Instant::now();
+        let mut t = 0;
+        for _ in 0..4 {
+            calm_window(&mut c, ticks(start, t));
+            t += 1;
+        }
+        climb_to(&mut c, start, &mut t, 400_000);
+        let at = c.current_kbps;
+        let r1 = stall_choke(&mut c, start, &mut t).expect("stall damage still backs off");
+        assert!(
+            c.decode_cap_kbps.is_none(),
+            "one starved window must not latch"
+        );
+        assert_eq!(
+            c.decode_backoff_kbps, 0,
+            "a starved window is not a knee sample — no reference recorded"
+        );
+        c.on_ack(r1);
+        climb_to(&mut c, start, &mut t, at - at / DECODE_CAP_SIMILAR_DIV);
+        let r2 = stall_choke(&mut c, start, &mut t).expect("second stall edge backs off too");
+        c.on_ack(r2);
+        assert!(
+            c.decode_cap_kbps.is_none(),
+            "a starved pair at the same rate must not latch a phantom knee"
+        );
+    }
+
+    #[test]
+    fn starved_window_preserves_the_knee_reference() {
+        // A REAL knee sample, then a stall edge, then the genuine re-climb choke: the starved
+        // window in the middle must neither latch nor ERASE the reference the real choke set —
+        // the genuine pair must still find each other around it.
+        let mut c = BitrateController::new(500_000);
+        c.set_ceiling(900_000);
+        let start = Instant::now();
+        let mut t = 0;
+        for _ in 0..4 {
+            calm_window(&mut c, ticks(start, t));
+            t += 1;
+        }
+        let knee = c.current_kbps;
+        let r1 = choke(&mut c, start, &mut t).expect("real choke backs off");
+        assert_eq!(
+            c.decode_backoff_kbps, knee,
+            "real choke records the reference"
+        );
+        c.on_ack(r1);
+        climb_to(&mut c, start, &mut t, knee - knee / DECODE_CAP_SIMILAR_DIV);
+        let r2 = stall_choke(&mut c, start, &mut t).expect("stall edge backs off");
+        assert_eq!(
+            c.decode_backoff_kbps, knee,
+            "the starved window must not erase the real reference"
+        );
+        assert!(c.decode_cap_kbps.is_none(), "and must not latch against it");
+        c.on_ack(r2);
+        climb_to(&mut c, start, &mut t, knee - knee / DECODE_CAP_SIMILAR_DIV);
+        let rate = c.current_kbps;
+        choke(&mut c, start, &mut t).expect("genuine re-climb choke backs off");
+        assert_eq!(
+            c.decode_cap_kbps,
+            Some(rate - rate / 16),
+            "the genuine pair still latches around the starved interruption"
+        );
+    }
+
     #[test]
     fn decode_cap_latches_when_the_reclimb_chokes_at_the_same_knee() {
         // The 1440p120 field sawtooth: a decoder knee (~500 Mbps) well under the (inflated)

crates/punktfunk-core/src/client/mod.rs

@@ -16,11 +16,13 @@ use crate::config::{CompositorPref, GamepadPref, Mode};
 use crate::error::{PunktfunkError, Result};
 use crate::input::InputEvent;
 use crate::quic::{
-    endpoint, ClipControl, ClipKind, ClipOffer, ColorInfo, HdrMeta, HidOutput, ProbeRequest,
-    RfiRequest, RichInput,
+    endpoint, ClipControl, ClipKind, ClipOffer, ColorInfo, HdrMeta, HidOutput, PadAudioFrame,
+    ProbeRequest, RfiRequest, RichInput,
 };
 use crate::session::Frame;
-use std::sync::atomic::{AtomicBool, AtomicI64, AtomicU16, AtomicU32, AtomicU64, Ordering};
+use std::sync::atomic::{
+    AtomicBool, AtomicI64, AtomicU16, AtomicU32, AtomicU64, AtomicU8, Ordering,
+};
 use std::sync::mpsc::{Receiver, RecvTimeoutError};
 use std::sync::{Arc, Mutex};
 use std::time::{Duration, Instant};
@@ -43,7 +45,7 @@ use self::control::{CtrlRequest, Negotiated};
 use self::frame_channel::{DecodeLatAcc, FrameChannel, FramePop};
 use self::planes::{
     RumbleUpdate, AUDIO_QUEUE, CLIP_EVENT_QUEUE, CURSOR_SHAPE_QUEUE, CURSOR_STATE_QUEUE,
-    HDR_META_QUEUE, HIDOUT_QUEUE, HOST_TIMING_QUEUE, RUMBLE_QUEUE,
+    HDR_META_QUEUE, HIDOUT_QUEUE, HOST_TIMING_QUEUE, PAD_AUDIO_QUEUE, RUMBLE_QUEUE,
 };
 use self::probe::ProbeState;
 use self::pump::run_pump;
@@ -122,6 +124,14 @@ pub struct NativeClient {
     rumble_sched: Arc<rumble::RumbleShared>,
     /// Inbound DualSense feedback (lightbar / player LEDs / adaptive triggers) — 0xCD datagrams.
     hidout: Mutex<Receiver<HidOutput>>,
+    /// Inbound pad audio (DualSense voice-coil haptics + speaker Opus frames) — 0xD1 datagrams.
+    /// Only a session that advertised [`quic::CLIENT_CAP_PAD_AUDIO`] against a
+    /// [`quic::HOST_CAP_PAD_AUDIO`] host ever receives any.
+    pad_audio: Mutex<Receiver<PadAudioFrame>>,
+    /// Per-pad pad-audio render capabilities (bit0 haptics, bit1 speaker), written by
+    /// [`NativeClient::set_pad_audio_caps`] and OR'd into outgoing gamepad-arrival flags
+    /// (bits 8/9) by the worker's input task — toward a `HOST_CAP_PAD_AUDIO` host only.
+    pad_audio_caps: Arc<[AtomicU8; crate::input::MAX_PADS]>,
     /// Inbound static HDR metadata (ST.2086 mastering + content light level) — 0xCE datagrams.
     hdr_meta: Mutex<Receiver<HdrMeta>>,
     /// Inbound per-AU host capture→send timings — 0xCF datagrams (the client always advertises
@@ -418,6 +428,10 @@ impl NativeClient {
         let rumble_sched = Arc::new(rumble::RumbleShared::new());
         let rumble_feed = rumble::RumbleFeed(rumble_sched.clone());
         let (hidout_tx, hidout_rx) = std::sync::mpsc::sync_channel::<HidOutput>(HIDOUT_QUEUE);
+        let (pad_audio_tx, pad_audio_rx) =
+            std::sync::mpsc::sync_channel::<PadAudioFrame>(PAD_AUDIO_QUEUE);
+        let pad_audio_caps: Arc<[AtomicU8; crate::input::MAX_PADS]> =
+            Arc::new(std::array::from_fn(|_| AtomicU8::new(0)));
         let (hdr_meta_tx, hdr_meta_rx) = std::sync::mpsc::sync_channel::<HdrMeta>(HDR_META_QUEUE);
         let (host_timing_tx, host_timing_rx) =
             std::sync::mpsc::sync_channel::<crate::quic::HostTiming>(HOST_TIMING_QUEUE);
@@ -459,6 +473,7 @@ impl NativeClient {
         let clock_offset_w = clock_offset.clone();
         let decode_lat_w = decode_lat.clone();
         let live_bitrate_w = live_bitrate.clone();
+        let pad_audio_caps_w = pad_audio_caps.clone();
         let ctrl_tx_pump = ctrl_tx.clone(); // the data-plane pump sends adaptive-FEC LossReports
         let worker = std::thread::Builder::new()
             .name("punktfunk-client".into())
@@ -508,6 +523,8 @@ impl NativeClient {
                     rumble_tx,
                     rumble_feed,
                     hidout_tx,
+                    pad_audio_tx,
+                    pad_audio_caps: pad_audio_caps_w,
                     hdr_meta_tx,
                     host_timing_tx,
                     cursor_shape_tx,
@@ -556,6 +573,8 @@ impl NativeClient {
             rumble: Mutex::new(rumble_rx),
             rumble_sched,
             hidout: Mutex::new(hidout_rx),
+            pad_audio: Mutex::new(pad_audio_rx),
+            pad_audio_caps,
             hdr_meta: Mutex::new(hdr_meta_rx),
             host_timing: Mutex::new(host_timing_rx),
             cursor_shape: Mutex::new(cursor_shape_rx),
@@ -1061,6 +1080,33 @@ impl NativeClient {
         }
     }
 
+    /// Pull the next pad-audio frame (0xD1): one Opus frame of DualSense voice-coil haptics
+    /// ([`quic::PAD_AUDIO_KIND_HAPTICS`], 5 ms) or built-in-speaker audio
+    /// ([`quic::PAD_AUDIO_KIND_SPEAKER`], 10 ms) for gamepad `pad`. All pads/kinds share the
+    /// queue — the embedder fans out by `pad`/`kind` to per-actuator Opus decoders. `None` on
+    /// timeout AND once the session ended ([`is_session_ended`](Self::is_session_ended)
+    /// distinguishes, and the plane is best-effort either way). Only a session that advertised
+    /// [`quic::CLIENT_CAP_PAD_AUDIO`] against a [`quic::HOST_CAP_PAD_AUDIO`] host — with the
+    /// pad's render caps declared via [`set_pad_audio_caps`](Self::set_pad_audio_caps) — ever
+    /// receives any. Drain on a dedicated thread like [`next_audio`](Self::next_audio); one
+    /// puller per the plane contract.
+    pub fn next_pad_audio(&self, timeout: Duration) -> Option<PadAudioFrame> {
+        self.pad_audio.lock().unwrap().recv_timeout(timeout).ok()
+    }
+
+    /// Declare wire pad `pad`'s pad-audio render capabilities: `audio_caps` bit0 = the pad can
+    /// play the HAPTICS stream (a real DualSense's voice coils), bit1 = the SPEAKER stream.
+    /// Call at controller attach, BEFORE the pad's arrival is sent (like
+    /// [`set_rumble_quirks`](Self::set_rumble_quirks)) — the worker ORs the bits into the
+    /// arrival's flags (bits 8/9), and only toward a [`quic::HOST_CAP_PAD_AUDIO`] host, so an
+    /// embedder that never calls this (or a host that can't capture pad audio) leaves the wire
+    /// bytes exactly as before. Latest-wins per pad; unknown bits are masked off.
+    pub fn set_pad_audio_caps(&self, pad: u8, audio_caps: u8) {
+        if let Some(slot) = self.pad_audio_caps.get(pad as usize) {
+            slot.store(audio_caps & 0x03, Ordering::Relaxed);
+        }
+    }
+
     /// Pull the next static HDR metadata update (ST.2086 mastering display + content light level)
     /// the host sent for an HDR session; same timeout/closed semantics as
     /// [`NativeClient::next_hidout`]. The host sends one near session start and re-sends it on

crates/punktfunk-core/src/client/planes.rs

@@ -20,6 +20,12 @@ pub(crate) type RumbleUpdate = (u16, u16, u16, Option<u16>);
 /// Same overflow discipline as rumble; the host re-sends on the next feedback change.
 pub(crate) const HIDOUT_QUEUE: usize = 32;
 
+/// Pad-audio frames (`0xD1` — DualSense voice-coil haptics + speaker) buffered for the embedder,
+/// ALL pads and kinds on one queue (the embedder fans out by `pad`/`kind`): 64 × 5 ms = 320 ms of
+/// slack on a haptics-only stream, the [`AUDIO_QUEUE`] discipline. A lagging embedder drops the
+/// newest frame (the renderer conceals the gap).
+pub(crate) const PAD_AUDIO_QUEUE: usize = 64;
+
 /// Static HDR metadata (ST.2086 mastering + content light level) buffered for the embedder. Tiny
 /// and low-rate (one on start, re-sent on mastering changes / keyframes); a small ring is ample.
 pub(crate) const HDR_META_QUEUE: usize = 8;

crates/punktfunk-core/src/client/pump.rs

@@ -50,6 +50,8 @@ pub(super) async fn run_pump(args: WorkerArgs) {
         rumble_tx,
         rumble_feed,
         hidout_tx,
+        pad_audio_tx,
+        pad_audio_caps,
         hdr_meta_tx,
         host_timing_tx,
         cursor_shape_tx,
@@ -92,9 +94,17 @@ pub(super) async fn run_pump(args: WorkerArgs) {
 
     // Input task: embedder events → uplink datagrams, with per-transition gamepad events
     // folded into idempotent seq-stamped snapshots toward a HOST_CAP_GAMEPAD_STATE host
-    // (see [`input_task`]).
+    // (see [`input_task`]). Pad-audio render caps ride arrival flags bits 8/9 ONLY toward a
+    // HOST_CAP_PAD_AUDIO host — an older host reads the whole flags word as the pad index.
     let gamepad_snapshots = host_caps & crate::quic::HOST_CAP_GAMEPAD_STATE != 0;
-    tokio::spawn(input_task::run(conn.clone(), input_rx, gamepad_snapshots));
+    let pad_audio_arrivals = host_caps & crate::quic::HOST_CAP_PAD_AUDIO != 0;
+    tokio::spawn(input_task::run(
+        conn.clone(),
+        input_rx,
+        gamepad_snapshots,
+        pad_audio_arrivals,
+        pad_audio_caps,
+    ));
 
     // Mic task: embedder Opus mic frames → 0xCB uplink datagrams (best-effort, dropped on loss).
     // Self-healing latency bound: every frame still queued once this task catches up is standing
@@ -166,6 +176,7 @@ pub(super) async fn run_pump(args: WorkerArgs) {
         rumble_tx,
         rumble_feed,
         hidout_tx,
+        pad_audio_tx,
         hdr_meta_tx,
         host_timing_tx,
         encode_lat.clone(),

crates/punktfunk-core/src/client/pump/datagram_task.rs

@@ -12,6 +12,7 @@ pub(super) async fn run(
     rumble_tx: std::sync::mpsc::SyncSender<RumbleUpdate>,
     rumble_feed: super::super::rumble::RumbleFeed,
     hidout_tx: std::sync::mpsc::SyncSender<crate::quic::HidOutput>,
+    pad_audio_tx: std::sync::mpsc::SyncSender<crate::quic::PadAudioFrame>,
     hdr_meta_tx: std::sync::mpsc::SyncSender<crate::quic::HdrMeta>,
     host_timing_tx: std::sync::mpsc::SyncSender<crate::quic::HostTiming>,
     // The ABR encode signal's accumulator (see [`EncodeLatAcc`]) — fed HERE, not off
@@ -60,22 +61,28 @@ pub(super) async fn run(
             }
             Some(&crate::quic::RUMBLE_MAGIC) => {
                 if let Some(u) = crate::quic::decode_rumble_envelope(&d) {
+                    // A pad index the client cannot represent is dropped outright, before either
+                    // consumer sees it. It used to be waved through: the seq gate was skipped (its
+                    // per-pad cursor has no slot for it) and it was handed to the legacy queue,
+                    // while the policy engine silently discarded it on its own bounds check — so
+                    // "both consumers are fed" below was false for exactly these, and an embedder
+                    // draining the queue could be handed an index it would use to subscript its
+                    // own per-pad array. The host never emits one; this is malformed or hostile.
+                    let idx = u.pad as usize;
+                    if idx >= crate::input::MAX_PADS {
+                        continue;
+                    }
                     // Gate v2 envelopes on their per-pad seq; forward v1 (envelope: None) as-is.
                     let fresh = match u.envelope {
                         Some(env) => {
-                            let idx = u.pad as usize;
-                            if idx < crate::input::MAX_PADS {
-                                if crate::input::GamepadSnapshot::seq_newer(
-                                    env.seq,
-                                    rumble_last_seq[idx],
-                                ) {
-                                    rumble_last_seq[idx] = Some(env.seq);
-                                    true
-                                } else {
-                                    false // reordered/duplicate — drop, keep the newer state
-                                }
+                            if crate::input::GamepadSnapshot::seq_newer(
+                                env.seq,
+                                rumble_last_seq[idx],
+                            ) {
+                                rumble_last_seq[idx] = Some(env.seq);
+                                true
                             } else {
-                                true // out-of-range pad (host never sends these): no gate
+                                false // reordered/duplicate — drop, keep the newer state
                             }
                         }
                         None => true,
@@ -94,6 +101,11 @@ pub(super) async fn run(
                     let _ = hidout_tx.try_send(h);
                 }
             }
+            Some(&crate::quic::PAD_AUDIO_MAGIC) => {
+                if let Some(f) = crate::quic::decode_pad_audio_datagram(&d) {
+                    let _ = pad_audio_tx.try_send(f);
+                }
+            }
             Some(&crate::quic::HDR_META_MAGIC) => {
                 if let Some(m) = crate::quic::decode_hdr_meta_datagram(&d) {
                     let _ = hdr_meta_tx.try_send(m);

crates/punktfunk-core/src/client/pump/input_task.rs

@@ -15,8 +15,16 @@ pub(super) async fn run(
     conn: quinn::Connection,
     mut input_rx: tokio::sync::mpsc::UnboundedReceiver<InputEvent>,
     gamepad_snapshots: bool,
+    // Whether the host advertised HOST_CAP_PAD_AUDIO: only then do arrivals carry the per-pad
+    // audio-render bits (flags 8/9) — an older host reads the whole flags word as the pad index,
+    // so unexpected high bits would make it drop the kind declaration entirely.
+    pad_audio: bool,
+    // Per-pad audio-render capabilities (bit0 haptics, bit1 speaker), fed by the embedder via
+    // [`NativeClient::set_pad_audio_caps`] and by arrival events already carrying the bits.
+    pad_audio_caps: std::sync::Arc<[std::sync::atomic::AtomicU8; crate::input::MAX_PADS]>,
 ) {
     use crate::input::{GamepadSnapshot, InputKind, MAX_PADS};
+    use std::sync::atomic::Ordering;
     // Touched pads only: an entry appears on the first gamepad event for that index, so the
     // refresh never conjures a virtual pad the embedder didn't drive.
     let mut pads: [Option<GamepadSnapshot>; MAX_PADS] = [None; MAX_PADS];
@@ -37,6 +45,28 @@ pub(super) async fn run(
     const ARRIVAL_RESENDS: u8 = 2;
     let mut arrival: [Option<u8>; MAX_PADS] = [None; MAX_PADS];
     let mut arrival_owed: [u8; MAX_PADS] = [0; MAX_PADS];
+    // An arrival's outgoing flags word: the pad index, plus the pad's audio-render bits (8/9)
+    // toward a HOST_CAP_PAD_AUDIO host. With no declared caps (or an older host) this is
+    // byte-identical to the plain index — the pre-pad-audio wire.
+    // B7: the caps a pad's LAST arrival actually carried. `set_pad_audio_caps` only stores into
+    // the registry — it cannot reach this task — so a declaration that lands after the arrival
+    // burst has drained (the renderer commits the trade only once its sink opens, which is well
+    // past the two 100 ms ticks) used to never reach the host at all: the client believed it had
+    // pad audio and the host emitted nothing on 0xD1, silently, forever. Comparing this against
+    // the live registry on every tick re-arms the burst by itself, with no new plumbing and no
+    // extra traffic when nothing changed.
+    let mut arrival_caps_sent: [u8; MAX_PADS] = [0; MAX_PADS];
+    let caps_now = |idx: usize| -> u8 {
+        if pad_audio {
+            pad_audio_caps[idx].load(Ordering::Relaxed)
+        } else {
+            0
+        }
+    };
+    let arrival_flags = |idx: usize| -> u32 {
+        let caps = caps_now(idx);
+        crate::input::encode_gamepad_arrival(idx as u8, caps)
+    };
     let mut refresh = tokio::time::interval(Duration::from_millis(100));
     refresh.set_missed_tick_behavior(tokio::time::MissedTickBehavior::Delay);
     loop {
@@ -81,30 +111,56 @@ pub(super) async fn run(
                     let _ = conn.send_datagram(rem.encode().to_vec().into());
                     continue;
                 }
-                if gamepad_snapshots && ev.kind == InputKind::GamepadArrival && idx < MAX_PADS {
-                    // Remember the declared kind (`code`) and forward it, arming a re-send burst
-                    // so the host learns it before the pad's first frame even under loss.
-                    arrival[idx] = Some(ev.code as u8);
-                    arrival_owed[idx] = ARRIVAL_RESENDS;
-                    let _ = conn.send_datagram(ev.encode().to_vec().into());
-                    continue;
+                if gamepad_snapshots && ev.kind == InputKind::GamepadArrival {
+                    // The index is the LOW BYTE only — bits 8/9 may carry the pad's audio-render
+                    // caps (an embedder building raw events; the `set_pad_audio_caps` registry is
+                    // the usual source). Fold event-carried bits into the registry so the re-send
+                    // burst keeps them, then send with the negotiation-gated flags word.
+                    let (pad, ev_caps) = crate::input::decode_gamepad_arrival(ev.flags);
+                    let idx = pad as usize;
+                    if idx < MAX_PADS {
+                        if ev_caps != 0 {
+                            pad_audio_caps[idx].fetch_or(ev_caps, Ordering::Relaxed);
+                        }
+                        // Remember the declared kind (`code`) and forward it, arming a re-send
+                        // burst so the host learns it before the pad's first frame even under loss.
+                        arrival[idx] = Some(ev.code as u8);
+                        arrival_owed[idx] = ARRIVAL_RESENDS;
+                        arrival_caps_sent[idx] = caps_now(idx);
+                        let arr = crate::input::InputEvent {
+                            flags: arrival_flags(idx),
+                            ..ev
+                        };
+                        let _ = conn.send_datagram(arr.encode().to_vec().into());
+                        continue;
+                    }
                 }
                 let _ = conn.send_datagram(ev.encode().to_vec().into());
             }
             _ = refresh.tick() => {
                 for idx in 0..MAX_PADS {
+                    // B7: caps declared after the burst drained — re-announce this pad's arrival.
+                    // Only for a pad that HAS an arrival (so it is a live, declared controller),
+                    // and only when the value actually moved, so a steady session sends nothing.
+                    if arrival[idx].is_some()
+                        && arrival_owed[idx] == 0
+                        && caps_now(idx) != arrival_caps_sent[idx]
+                    {
+                        arrival_owed[idx] = ARRIVAL_RESENDS;
+                    }
                     // Re-send an owed kind declaration (independent of whether the pad has state
                     // yet — it may be idle-but-connected). Idempotent on the host.
                     if arrival_owed[idx] > 0 {
                         if let Some(kind) = arrival[idx] {
                             arrival_owed[idx] -= 1;
+                            arrival_caps_sent[idx] = caps_now(idx);
                             let arr = crate::input::InputEvent {
                                 kind: InputKind::GamepadArrival,
                                 _pad: [0; 3],
                                 code: kind as u32,
                                 x: 0,
                                 y: 0,
-                                flags: idx as u32,
+                                flags: arrival_flags(idx),
                             };
                             let _ = conn.send_datagram(arr.encode().to_vec().into());
                         } else {

crates/punktfunk-core/src/client/rumble.rs

@@ -36,6 +36,22 @@ pub const LEGACY_STALE_MS: u64 = 1000;
 /// engine's staleness zero lands at 1 s; this is the hardware-level net under an engine stall).
 const BACKSTOP_LEGACY_MS: u32 = 2000;
 
+/// The longest lease the engine honours, whatever the envelope claims — the receiver-side mirror of
+/// the host's own `RUMBLE_TTL_CEIL_MS`.
+///
+/// No host built from this tree can exceed it (the `PUNKTFUNK_RUMBLE_TTL_MS` hatch is clamped to
+/// `[150, 5000]` before it reaches the wire), so this is defence in depth against a third-party or
+/// modified sender that stamps a long TTL and then wedges its renewal pump while the connection
+/// stays up. It matters on exactly the platforms that sustain a level for the whole lease: Apple,
+/// whose renderer deliberately keeps no staleness policy of its own, and a Deck slot, whose
+/// keepalive re-kicks the actuator until the lease ends. Duration-parameterized embedders (SDL,
+/// Android) already self-terminate at the clamped backstop.
+///
+/// Deliberately NOT `pub`: an embedder has no use for it, and every `pub` const in this crate is
+/// emitted into `include/punktfunk_core.h` as an UNPREFIXED `#define` — a collision hazard the
+/// header already has ~170 instances of, and one this has no reason to add to.
+const MAX_LEASE_MS: u16 = 5_000;
+
 /// One effective actuator command. `(0, 0)` means stop now. `backstop_ms` is a safety-net
 /// duration for platform APIs that take one (SDL rumble, Android one-shots): the engine emits
 /// explicit zeros at every policy stop, so the backstop only matters if the embedder thread itself
@@ -53,10 +69,25 @@ pub struct RumbleCommand {
 #[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
 pub struct ActuatorQuirks {
     /// Re-emit an unchanged non-zero level every this many ms — for actuators whose hardware
-    /// output decays between wire renewals (Steam Deck ≈ 40, macOS DualSense-over-HID BT ≈ 900).
-    /// `0` = no keepalive (the common case).
+    /// output decays between wire renewals. `0` = no keepalive (the common case).
+    ///
+    /// The one in-tree producer is the Steam Deck's ≈ 40 ms (`pf-client-core`'s slot open, paired
+    /// with `dedup_jitter`). The macOS DualSense-over-HID Bluetooth decay is NOT served by this
+    /// quirk, though it reads like the obvious second example: the Apple client keeps its own
+    /// ≈ 900 ms keepalive down in `RumbleRenderer` (`RumbleTuning.hidKeepaliveSeconds`) because
+    /// the re-emit has to happen BELOW the command layer. An engine keepalive arrives as a
+    /// command carrying the same levels, and that renderer skips a HID write whose levels are
+    /// unchanged — so the re-emit would be swallowed by the very dedupe it exists to defeat
+    /// (`dedup_jitter` is the Deck's answer to the same problem one layer up).
     pub keepalive_ms: u16,
-    /// Floor for `backstop_ms` on non-zero commands (Android's `createOneShot` throws on 0).
+    /// Floor for `backstop_ms` on non-zero commands.
+    ///
+    /// **No in-tree producer sets this non-zero** — it is reachable only through the C ABI
+    /// (`punktfunk_connection_set_rumble_quirks`), for embedders whose duration-taking API
+    /// rejects short values. The case it was written for is handled elsewhere: Android's
+    /// `createOneShot` does throw on a non-positive duration, but the Kotlin renderer floors the
+    /// duration itself at the call, and that path never declares quirks at all. Kept because it
+    /// is exported ABI, and because a floor belongs here rather than re-invented per embedder.
     pub min_pulse_ms: u16,
     /// Alternate the low motor's LSB on keepalive re-emits (imperceptible) so an SDL-class layer
     /// that no-ops identical values still writes the device — the Deck's dedupe-defeat.
@@ -75,8 +106,11 @@ struct PadState {
     /// A wire update landed since the last emit (level change OR renewal — renewals re-emit).
     dirty: bool,
     next_keepalive: Option<Instant>,
-    /// Current jitter phase (see [`ActuatorQuirks::dedup_jitter`]).
-    jitter: bool,
+    /// The exact value last handed to an embedder. `(0, 0)` ⇔ the engine believes this actuator is
+    /// silent. It replaces a free-running jitter phase because one field answers all three live
+    /// questions: would re-sending this be a no-op device write (the dedupe nudge), is a stop
+    /// redundant, and would the nudge synthesize the reserved stop.
+    last_emit: (u16, u16),
     quirks: ActuatorQuirks,
 }
 
@@ -88,7 +122,7 @@ impl PadState {
         legacy_wire: None,
         dirty: false,
         next_keepalive: None,
-        jitter: false,
+        last_emit: (0, 0),
         quirks: ActuatorQuirks {
             keepalive_ms: 0,
             min_pulse_ms: 0,
@@ -112,6 +146,7 @@ impl PadState {
         self.legacy_wire = None;
         self.next_keepalive = None;
         self.dirty = false;
+        self.last_emit = (0, 0);
         RumbleCommand {
             pad,
             low: 0,
@@ -119,6 +154,40 @@ impl PadState {
             backstop_ms: 0,
         }
     }
+
+    /// Build the command for the pad's current level, and record what we handed out.
+    ///
+    /// On a `dedup_jitter` actuator, re-emitting the value the device last took is a no-op write on
+    /// an SDL-class layer, so the low motor's LSB is nudged. Keying that on `last_emit` rather than
+    /// on a free-running phase is what makes it work on EVERY emit path. Previously the nudge lived
+    /// only in the keepalive branch, so a host renewal — which arrives every `ttl*3/10` ms, 120 ms
+    /// at the 400 ms default and 60 ms at the hatch floor — re-emitted the raw level, collided with
+    /// the last jittered write, was swallowed, AND re-anchored the keepalive. That stretched the
+    /// gap between *distinct* device writes to 80 ms at the default cadence and 100 ms at the
+    /// floor, on an actuator whose quirk declares 40.
+    ///
+    /// The nudge is refused when it would synthesize the reserved `(0, 0)` stop. That is level
+    /// `(1, 0)` and only that: `high` must already be 0, and `low ^ 1 == 0` implies `low == 1`.
+    /// There the LSB steps up instead, so the phase still alternates (1 ↔ 3, two parts in 65535)
+    /// and the pad never receives a stop the policy did not order.
+    fn emit(&mut self, pad: u16) -> RumbleCommand {
+        let (mut low, high) = self.level;
+        if self.quirks.dedup_jitter && (low, high) == self.last_emit {
+            let alt = low ^ 1;
+            low = if (alt, high) == (0, 0) {
+                low | 0b10
+            } else {
+                alt
+            };
+        }
+        self.last_emit = (low, high);
+        RumbleCommand {
+            pad,
+            low,
+            high,
+            backstop_ms: self.backstop(),
+        }
+    }
 }
 
 /// The pure per-connection policy state machine. Time is always passed in (`now`) so the policy
@@ -156,6 +225,8 @@ impl RumbleEngine {
         p.dirty = true;
         match ttl_ms {
             Some(t) => {
+                // Never honour a lease longer than [`MAX_LEASE_MS`], whatever the sender claims.
+                let t = t.min(MAX_LEASE_MS);
                 p.ttl_ms = t;
                 p.legacy_wire = None;
                 p.deadline = if (low, high) != (0, 0) {
@@ -214,22 +285,25 @@ impl RumbleEngine {
             if p.dirty {
                 p.dirty = false;
                 if p.level == (0, 0) {
-                    return (Some(p.silence(pad)), None);
+                    // Relay a stop only if the actuator is, as far as the engine knows, still
+                    // buzzing. A zero on an already-silent pad heals nothing and costs every
+                    // embedder a command — Android an unconditional log line plus a binder
+                    // `cancel()`. Two senders produce them: the host's deliberate
+                    // `RUMBLE_STOP_BURST` re-sends after the first stop already landed, and (behind
+                    // `PUNKTFUNK_RUMBLE_ENVELOPE=0`) the legacy flat 500 ms refresh, which re-sends
+                    // zeros for every latched pad for the rest of the session. The burst still
+                    // heals the case it exists for: a LOST first stop leaves the pad buzzing, so
+                    // `last_emit != (0, 0)` and the re-send does emit.
+                    if p.last_emit != (0, 0) {
+                        return (Some(p.silence(pad)), None);
+                    }
+                    continue;
                 }
                 if p.quirks.keepalive_ms > 0 {
                     p.next_keepalive =
                         Some(now + Duration::from_millis(p.quirks.keepalive_ms as u64));
                 }
-                let (low, high) = p.level;
-                return (
-                    Some(RumbleCommand {
-                        pad,
-                        low,
-                        high,
-                        backstop_ms: p.backstop(),
-                    }),
-                    None,
-                );
+                return (Some(p.emit(pad)), None);
             }
             // 4) actuator-decay keepalive, bounded by (1)/(2) above by construction: an expired
             // or stale pad was silenced before reaching here, so a keepalive can never sustain a
@@ -239,20 +313,7 @@ impl RumbleEngine {
                 let due = *p.next_keepalive.get_or_insert(now + ka);
                 if now >= due {
                     p.next_keepalive = Some(now + ka);
-                    let (mut low, high) = p.level;
-                    if p.quirks.dedup_jitter {
-                        p.jitter = !p.jitter;
-                        low ^= p.jitter as u16;
-                    }
-                    return (
-                        Some(RumbleCommand {
-                            pad,
-                            low,
-                            high,
-                            backstop_ms: p.backstop(),
-                        }),
-                        None,
-                    );
+                    return (Some(p.emit(pad)), None);
                 }
                 merge_wake(&mut wake, due);
             }
@@ -357,6 +418,22 @@ pub(crate) struct Closed;
 mod tests {
     use super::*;
 
+    /// The Steam Deck's declared quirks — the only shipping actuator with `dedup_jitter`.
+    const DECK: ActuatorQuirks = ActuatorQuirks {
+        keepalive_ms: 40,
+        min_pulse_ms: 0,
+        dedup_jitter: true,
+    };
+
+    /// Drain the engine the way an embedder does: poll until nothing is due.
+    fn drain(e: &mut RumbleEngine, t: Instant) -> Vec<(u16, u16)> {
+        let mut out = Vec::new();
+        while let (Some(c), _) = e.poll(t) {
+            out.push((c.low, c.high));
+        }
+        out
+    }
+
     fn ms(v: u64) -> Duration {
         Duration::from_millis(v)
     }
@@ -527,4 +604,133 @@ mod tests {
         );
         assert_eq!(shared.next_command(ms(10)), Err(Closed));
     }
+
+    /// A host renewal must not repeat the value the device last took, or an SDL-class layer
+    /// swallows the write. Before the jitter moved onto every emit path it lived only in the
+    /// keepalive branch, so each renewal collided with the last jittered write and was deduped.
+    #[test]
+    fn renewal_keeps_the_dedupe_jitter_alternating() {
+        let mut e = RumbleEngine::new();
+        e.set_quirks(0, DECK);
+        let t0 = Instant::now();
+        e.wire_update(t0, 0, 100, 200, Some(400));
+        assert_eq!(drain(&mut e, t0), vec![(100, 200)]);
+        assert_eq!(drain(&mut e, t0 + ms(40)), vec![(101, 200)]);
+        assert_eq!(drain(&mut e, t0 + ms(80)), vec![(100, 200)]);
+        // The renewal at the 120 ms default cadence: same level, must still be a distinct write.
+        e.wire_update(t0 + ms(120), 0, 100, 200, Some(400));
+        assert_eq!(drain(&mut e, t0 + ms(120)), vec![(101, 200)]);
+        assert_eq!(drain(&mut e, t0 + ms(160)), vec![(100, 200)]);
+    }
+
+    /// Phase-robust version of the same property, at the TTL hatch's 60 ms renewal floor: no two
+    /// consecutive DISTINCT device writes may be further apart than the declared 40 ms cadence.
+    #[test]
+    fn renewal_never_gaps_distinct_writes_at_the_60ms_floor() {
+        let mut e = RumbleEngine::new();
+        e.set_quirks(0, DECK);
+        let t0 = Instant::now();
+        let (mut last, mut last_write, mut worst) = ((0u16, 0u16), 0u64, 0u64);
+        for tick in 0..=360u64 {
+            let t = t0 + ms(tick);
+            if tick % 60 == 0 {
+                e.wire_update(t, 0, 100, 200, Some(400));
+            }
+            for v in drain(&mut e, t) {
+                assert_ne!(v, (0, 0), "a live lease must never emit the stop sentinel");
+                if v != last {
+                    worst = worst.max(tick - last_write);
+                    last_write = tick;
+                    last = v;
+                }
+            }
+        }
+        assert!(
+            worst <= 41,
+            "worst distinct-write gap {worst} ms exceeds the 40 ms declared cadence"
+        );
+    }
+
+    /// The nudge must stay behind `dedup_jitter`: an off-by-one amplitude on a default-quirks pad
+    /// would land in Apple's identical-target comparison and Android's one-shot amplitudes.
+    #[test]
+    fn default_quirks_pads_get_the_level_verbatim_on_every_renewal() {
+        let mut e = RumbleEngine::new(); // Apple / Android / plain SDL
+        let t0 = Instant::now();
+        e.wire_update(t0, 0, 100, 200, Some(400));
+        assert_eq!(e.poll(t0).0, Some(cmd(0, 100, 200, 800)));
+        e.wire_update(t0 + ms(120), 0, 100, 200, Some(400));
+        assert_eq!(e.poll(t0 + ms(120)).0, Some(cmd(0, 100, 200, 800)));
+    }
+
+    /// Level `(1, 0)` is the one value whose LSB flip is the reserved stop. The nudge steps up
+    /// instead, so the phase still alternates and no stop is invented under a live lease.
+    #[test]
+    fn jitter_never_synthesizes_the_stop_sentinel() {
+        let mut e = RumbleEngine::new();
+        e.set_quirks(0, DECK);
+        let t0 = Instant::now();
+        e.wire_update(t0, 0, 1, 0, Some(400));
+        assert_eq!(e.poll(t0).0, Some(cmd(0, 1, 0, 800)));
+        assert_eq!(e.poll(t0 + ms(40)).0, Some(cmd(0, 3, 0, 800)));
+        assert_eq!(e.poll(t0 + ms(80)).0, Some(cmd(0, 1, 0, 800)));
+    }
+
+    /// A zero for a pad the engine already believes is silent is dropped: it heals nothing and
+    /// costs every embedder a command. The deliberate stop-burst heal is unaffected, because a
+    /// LOST stop leaves the pad buzzing and the re-send therefore does emit.
+    #[test]
+    fn a_redundant_stop_is_dropped_but_the_burst_still_heals_a_lost_one() {
+        let mut e = RumbleEngine::new();
+        let t0 = Instant::now();
+        e.wire_update(t0, 0, 100, 200, Some(400));
+        assert_eq!(drain(&mut e, t0), vec![(100, 200)]);
+        // First stop reaches the embedder…
+        e.wire_update(t0 + ms(10), 0, 0, 0, Some(0));
+        assert_eq!(drain(&mut e, t0 + ms(10)), vec![(0, 0)]);
+        // …and the burst re-sends behind it are now silent.
+        e.wire_update(t0 + ms(20), 0, 0, 0, Some(0));
+        e.wire_update(t0 + ms(30), 0, 0, 0, Some(0));
+        assert_eq!(drain(&mut e, t0 + ms(30)), Vec::new());
+
+        // But if the pad is buzzing (the stop that mattered was lost), a re-send still emits.
+        e.wire_update(t0 + ms(40), 0, 100, 200, Some(400));
+        assert_eq!(drain(&mut e, t0 + ms(40)), vec![(100, 200)]);
+        e.wire_update(t0 + ms(50), 0, 0, 0, Some(0));
+        assert_eq!(drain(&mut e, t0 + ms(50)), vec![(0, 0)]);
+    }
+
+    /// The client bounds the host's lease. `RUMBLE_TTL_CEIL_MS` is sender-side only, so a modified
+    /// or third-party host could otherwise stamp a huge TTL and wedge its pump, leaving Apple and
+    /// the Deck buzzing for the whole of it.
+    #[test]
+    fn an_overlong_lease_is_clamped_to_the_ceiling() {
+        let mut e = RumbleEngine::new();
+        let t0 = Instant::now();
+        e.wire_update(t0, 0, 100, 200, Some(u16::MAX));
+        assert_eq!(e.poll(t0).0, Some(cmd(0, 100, 200, 5000)));
+        // Silenced at the ceiling, not at the 65 s the sender asked for.
+        assert!(e.poll(t0 + ms(MAX_LEASE_MS as u64 - 1)).0.is_none());
+        assert_eq!(
+            e.poll(t0 + ms(MAX_LEASE_MS as u64)).0,
+            Some(cmd(0, 0, 0, 0)),
+            "the lease must end at the ceiling"
+        );
+    }
+
+    /// A v2 envelope carrying `ttl_ms == 0` on a LIVE level. The audit suspected the zero would be
+    /// mistaken for the legacy sentinel in `backstop()`; it cannot, because the expiry check
+    /// preempts the relay branch — the pad silences on the same poll and never reaches a backstop.
+    /// Pinned so that ordering stays load-bearing rather than incidental.
+    #[test]
+    fn a_zero_ttl_envelope_silences_rather_than_taking_the_legacy_backstop() {
+        let mut e = RumbleEngine::new();
+        let t0 = Instant::now();
+        e.wire_update(t0, 0, 100, 200, Some(0));
+        assert_eq!(
+            e.poll(t0).0,
+            Some(cmd(0, 0, 0, 0)),
+            "a zero-length lease must expire immediately, not emit with a legacy backstop"
+        );
+    }
 }

crates/punktfunk-core/src/client/worker.rs

@@ -5,8 +5,8 @@ use crate::clipboard::{ClipCommand, ClipEventCore};
 use crate::config::{CompositorPref, GamepadPref, Mode};
 use crate::error::Result;
 use crate::input::InputEvent;
-use crate::quic::{HdrMeta, HidOutput};
-use std::sync::atomic::{AtomicBool, AtomicI64, AtomicU32, AtomicU64};
+use crate::quic::{HdrMeta, HidOutput, PadAudioFrame};
+use std::sync::atomic::{AtomicBool, AtomicI64, AtomicU32, AtomicU64, AtomicU8};
 use std::sync::mpsc::SyncSender;
 use std::sync::{Arc, Mutex};
 
@@ -43,6 +43,14 @@ pub(crate) struct WorkerArgs {
     /// closed, so the command API always observes connection teardown.
     pub(crate) rumble_feed: super::rumble::RumbleFeed,
     pub(crate) hidout_tx: SyncSender<HidOutput>,
+    /// Inbound pad-audio frames (`0xD1` — DualSense voice-coil haptics + speaker), drained by
+    /// [`NativeClient::next_pad_audio`].
+    pub(crate) pad_audio_tx: SyncSender<PadAudioFrame>,
+    /// Per-pad pad-audio render capabilities (bit0 haptics, bit1 speaker), written by
+    /// [`NativeClient::set_pad_audio_caps`] and OR'd into outgoing
+    /// [`GamepadArrival`](crate::input::InputKind::GamepadArrival) flags (bits 8/9) by the input
+    /// task — toward a `HOST_CAP_PAD_AUDIO` host only.
+    pub(crate) pad_audio_caps: Arc<[AtomicU8; crate::input::MAX_PADS]>,
     pub(crate) hdr_meta_tx: SyncSender<HdrMeta>,
     pub(crate) host_timing_tx: SyncSender<crate::quic::HostTiming>,
     pub(crate) cursor_shape_tx: SyncSender<crate::quic::CursorShape>,

crates/punktfunk-core/src/input.rs

@@ -64,7 +64,11 @@ pub enum InputKind {
     GamepadRemove = 13,
     /// Declares which controller KIND a pad presents so a session can MIX types (pad 0 a
     /// DualSense, pad 1 an Xbox pad). `code` = the [`GamepadPref`](crate::config::GamepadPref)
-    /// wire byte, `flags` = pad index. Sent when the client opens a pad slot — before that pad's
+    /// wire byte, `flags` = pad index in the low byte plus the pad's render capabilities in bits
+    /// 8/9 ([`ARRIVAL_FLAG_PAD_AUDIO_HAPTICS`]/[`ARRIVAL_FLAG_PAD_AUDIO_SPEAKER`] — sent only
+    /// toward a [`HOST_CAP_PAD_AUDIO`](crate::quic::HOST_CAP_PAD_AUDIO) host, so an older host
+    /// keeps reading the whole word as the index; hosts decode via [`decode_gamepad_arrival`]).
+    /// Sent when the client opens a pad slot — before that pad's
     /// first input — and re-sent a few times against datagram loss (like [`GamepadRemove`]). The
     /// host resolves the kind to a buildable backend and routes that pad's virtual device to it; a
     /// pad the client never declares (an older client, or a fully-lost declaration) falls back to
@@ -97,6 +101,34 @@ pub fn decode_gamepad_remove(flags: u32) -> (u8, u8) {
     (flags as u8, (flags >> 24) as u8)
 }
 
+/// [`InputKind::GamepadArrival`] `flags` bit: this pad renders pad-audio HAPTICS — it is (or
+/// forwards to) a real DualSense whose voice-coil actuators can play the
+/// [`PAD_AUDIO_KIND_HAPTICS`](crate::quic::PAD_AUDIO_KIND_HAPTICS) stream. Rides above the pad
+/// index byte; sent only toward a [`HOST_CAP_PAD_AUDIO`](crate::quic::HOST_CAP_PAD_AUDIO) host
+/// (an older host reads the whole `flags` word as the index, so unexpected high bits would make
+/// it drop the declaration).
+pub const ARRIVAL_FLAG_PAD_AUDIO_HAPTICS: u32 = 1 << 8;
+/// [`InputKind::GamepadArrival`] `flags` bit: this pad renders pad-audio SPEAKER — the
+/// [`PAD_AUDIO_KIND_SPEAKER`](crate::quic::PAD_AUDIO_KIND_SPEAKER) stream. Same wire discipline
+/// as [`ARRIVAL_FLAG_PAD_AUDIO_HAPTICS`].
+pub const ARRIVAL_FLAG_PAD_AUDIO_SPEAKER: u32 = 1 << 9;
+
+/// Pack a [`InputKind::GamepadArrival`] `flags` word: the pad index in the low byte plus
+/// `audio_caps` (bit0 = haptics, bit1 = speaker) as bits 8/9. `audio_caps = 0` reproduces the
+/// pre-pad-audio wire bytes exactly.
+pub fn encode_gamepad_arrival(pad: u8, audio_caps: u8) -> u32 {
+    (pad as u32) | (((audio_caps & 0x03) as u32) << 8)
+}
+
+/// Unpack a [`InputKind::GamepadArrival`] `flags` word into `(pad, audio_caps)`. The pad index
+/// is `flags & 0xFF` — hosts MUST mask rather than take the whole word, or a capability bit
+/// reads as a phantom index; `audio_caps` is bits 8/9 (bit0 = haptics, bit1 = speaker — the
+/// [`ARRIVAL_FLAG_PAD_AUDIO_HAPTICS`]/[`ARRIVAL_FLAG_PAD_AUDIO_SPEAKER`] bits shifted down).
+/// An old-format word (index only) yields `audio_caps = 0`.
+pub fn decode_gamepad_arrival(flags: u32) -> (u8, u8) {
+    (flags as u8, ((flags >> 8) & 0x03) as u8)
+}
+
 /// The gamepad wire contract for [`InputKind::GamepadButton`]/[`InputKind::GamepadAxis`].
 ///
 /// Everything follows the GameStream/XInput conventions end to end: buttons reuse
@@ -348,6 +380,11 @@ pub enum GamepadEvent {
         kind: u8,
         /// LI_CCAP_* bits (0x02 = rumble).
         capabilities: u16,
+        /// Pad-audio render capabilities from a NATIVE-plane arrival's `flags` bits 8/9
+        /// (bit0 = haptics, bit1 = speaker — see [`decode_gamepad_arrival`]). NOT a GameStream
+        /// LI_CCAP bit (that vocabulary lives in `capabilities`); the GameStream plane cannot
+        /// express pad audio and always sets `0`, as does an old client.
+        audio_caps: u8,
     },
 }
 
@@ -443,6 +480,31 @@ mod tests {
         assert_eq!((pad, seq), (9, 123));
     }
 
+    #[test]
+    fn gamepad_arrival_flags_roundtrip() {
+        // The capability bits ride bits 8/9; the index stays the low byte.
+        for (pad, caps) in [(0u8, 0u8), (3, 0b01), (15, 0b10), (7, 0b11)] {
+            let flags = encode_gamepad_arrival(pad, caps);
+            assert_eq!(decode_gamepad_arrival(flags), (pad, caps));
+            assert_eq!(flags & 0xFF, pad as u32);
+        }
+        assert_eq!(
+            encode_gamepad_arrival(2, 0b11),
+            2 | ARRIVAL_FLAG_PAD_AUDIO_HAPTICS | ARRIVAL_FLAG_PAD_AUDIO_SPEAKER
+        );
+        // Old-format compat both ways: a caps-less word (an old client, or a new one toward an
+        // old host) is byte-identical to the plain index, and decodes with caps 0.
+        assert_eq!(encode_gamepad_arrival(5, 0), 5);
+        assert_eq!(decode_gamepad_arrival(5), (5, 0));
+        // Undefined high bits (a future extension) never leak into the index OR the caps.
+        assert_eq!(
+            decode_gamepad_arrival(0xFFFF_0000 | (0b01 << 8) | 9),
+            (9, 1)
+        );
+        // encode masks unknown caps bits, so a sloppy embedder can't corrupt the index space.
+        assert_eq!(encode_gamepad_arrival(1, 0xFF), 1 | (0b11 << 8));
+    }
+
     #[test]
     fn gamepad_snapshot_roundtrip() {
         let s = GamepadSnapshot {

crates/punktfunk-core/src/lib.rs

@@ -107,6 +107,10 @@ pub use stats::Stats;
 /// v10: added `punktfunk_connection_clock_offset_now_ns` — the LIVE (mid-stream re-synced)
 /// clock offset ongoing latency math must use; the connect-time getter stays frozen by
 /// contract. Additive, client-local — no wire change, so [`WIRE_VERSION`] is unchanged.
+/// v11: added `punktfunk_connect_ex9` — `connect_ex8` plus a `client_caps` bitfield
+/// (`PUNKTFUNK_CLIENT_CAP_CURSOR`, later `…_PHASE_LOCK`), which is how a client tells the host it
+/// renders the pointer itself. Additive; the caps ride the existing Hello, so [`WIRE_VERSION`] is
+/// unchanged. (Documented late — the bump shipped without its line here.)
 /// v12: added `punktfunk_connection_set_cursor_render` — the mid-stream cursor-render flip
 /// (design/remote-desktop-sweep.md §8): the client's mouse-model chord tells the host who
 /// renders the pointer. Additive; rides the existing control stream (a new message TYPE, which
@@ -120,7 +124,21 @@ pub use stats::Stats;
 /// uncertainty and the circular arrival-lead statistic the host's controller steers on. Additive;
 /// the wire grows only a new control message (`PhaseReport`, 0x32) an old host never reads and a
 /// strict-prefix append on the 0xCF host-timing tail, so [`WIRE_VERSION`] is unchanged.
-pub const ABI_VERSION: u32 = 14;
+/// v15: versions the shared rumble policy engine's C surface —
+/// `punktfunk_connection_next_rumble_cmd`, `punktfunk_connection_set_rumble_quirks` and the
+/// `PUNKTFUNK_RUMBLE_QUIRK_*` bits. These symbols are NOT new: they landed while this constant
+/// still read 7 and no bump was made, so every core since has exported them while advertising a
+/// version that never promised them. That cannot be corrected retroactively — a shipped binary
+/// says what it says — so v15 is the floor that *guarantees* them: at or above it the surface is
+/// present, below it an embedder must probe for the symbol. Purely a version statement; no code
+/// changed with this bump, and no wire change, so [`WIRE_VERSION`] is unchanged.
+/// v16: added the pad-audio client surface — `punktfunk_connection_next_pad_audio` (the 0xD1
+/// per-gamepad DualSense haptics/speaker plane) + `punktfunk_connection_set_pad_audio_caps` and
+/// the `PUNKTFUNK_CLIENT_CAP_PAD_AUDIO` / `PUNKTFUNK_HOST_CAP_PAD_AUDIO` mirrors. Additive and
+/// capability-gated end to end: the wire grows a new datagram tag (0xD1) an old client never
+/// receives (double-gated caps), a new 0xCD kind (0x06, dropped as unknown by old clients) and
+/// arrival flag bits 8/9 sent only toward a capable host, so [`WIRE_VERSION`] is unchanged.
+pub const ABI_VERSION: u32 = 16;
 
 /// The punktfunk/1 **wire** version — what `Hello`/`Welcome` carry and hosts equality-check.
 /// Deliberately its own constant: [`ABI_VERSION`] tracks the embeddable **C surface**

crates/punktfunk-core/src/phase.rs

@@ -129,6 +129,167 @@ pub fn circular_latch(samples_us: &[u64], period_ns: i64) -> Option<(u64, u16)>
     Some((mean_ns, (r * 1000.0) as u16))
 }
 
+/// Largest present spacing still treated as cadence. Anything wider is a stall (a stream pause,
+/// an occluded window, a codec rebuild) and is counted separately: folding a 5-second gap in as
+/// "one irregular interval" would be true but useless, and folding it in as several would make a
+/// single hitch dominate the window.
+const CADENCE_MAX_UNITS: usize = 8;
+
+/// A backwards step larger than this is not a reordered delivery, it is a bogus timestamp, and
+/// the run re-anchors onto the new instant instead of holding the old one. Android's render
+/// callback is documented to carry a garbage far-future stamp on a session's first frames;
+/// without this bound, holding "the later instant" latches onto that stamp and every subsequent
+/// present scores as disordered for the rest of the session (observed on glass, 2026-08-05).
+const CADENCE_REANCHOR_NS: i64 = 100_000_000;
+
+/// Minimum intervals before a cadence summary means anything — same evidence bar as
+/// [`circular_latch`]. At any sane frame rate a 1 s window clears this many times over; it is
+/// there so a window truncated by a reanchor does not publish a judder figure off three samples.
+const CADENCE_MIN_SAMPLES: u32 = 8;
+
+/// One window's present-cadence summary (see [`PresentIntervals`]).
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct PresentCadence {
+    /// The most common spacing, in whole panel refreshes. This is the stream's cadence ratio:
+    /// 1 when stream rate matches the panel, 2 for 60-on-120, 4 for 30-on-120.
+    pub mode_units: u8,
+    /// Fraction of intervals that were NOT the mode, in ‰ (same unit as the phase coherence).
+    /// **This is the judder number.** 0 = a perfectly regular cadence at any ratio.
+    pub judder_permille: u16,
+    /// Intervals folded into the histogram (excludes stalls and disordered samples).
+    pub samples: u32,
+    /// Spacings wider than [`CADENCE_MAX_UNITS`] — stalls, not judder. Reported so a window that
+    /// looks smooth *because the stream was paused* cannot be mistaken for a good one.
+    pub stalls: u32,
+    /// Present instants that did not advance (duplicate or out-of-order callbacks). A platform
+    /// bookkeeping signal, not a display defect — kept out of the judder ratio deliberately.
+    pub disordered: u32,
+}
+
+/// Present-interval distribution in whole panel refreshes — the cadence (judder) statistic.
+///
+/// Every other stat we publish is a latency: a difference between two points on one frame. No
+/// latency can see judder, because judder is a property of the *sequence*. A stream that shows
+/// each frame one refresh early and the next one late has excellent percentiles and looks
+/// broken; a stream whose every interval is exactly two refreshes has worse latency than one
+/// that alternates 1 and 3, and looks perfect. Quantising the spacing between consecutive
+/// on-glass instants onto the panel grid measures the thing the eye actually reacts to.
+///
+/// Scale-free by construction: it needs no reference clock, and the *mode* absorbs the cadence
+/// ratio, so 60-on-120 and 120-on-120 are both "smooth = one tall bucket" and comparable to each
+/// other. That is what makes it usable as one ruler across clients, refresh rates and stream
+/// rates — including for a feature-on/feature-off A/B on the same device.
+///
+/// Feed it the **measured on-glass instant**, never the instant a present was *requested*:
+/// requested times would measure our own intent and report a perfect cadence no matter what the
+/// display did with it. Every client has the real one (Android's `OnFrameRendered` system time,
+/// the desktop's `VK_KHR_present_wait` stamp, Apple's drawable `presentedTime`).
+///
+/// Pure state and arithmetic — no clock, no allocation. The caller owns the window: drain with
+/// [`take`](Self::take) on its own 1 s tumbling boundary, per `design/stats-unification.md`.
+#[derive(Debug, Clone, Default)]
+pub struct PresentIntervals {
+    last_present_ns: i64,
+    /// Counts indexed by whole refreshes, `0..=CADENCE_MAX_UNITS`.
+    hist: [u32; CADENCE_MAX_UNITS + 1],
+    samples: u32,
+    stalls: u32,
+    disordered: u32,
+}
+
+impl PresentIntervals {
+    pub fn new() -> PresentIntervals {
+        PresentIntervals::default()
+    }
+
+    /// Forget the previous instant without discarding the window's counts. Call on any
+    /// discontinuity where the next present is not a continuation of this cadence (reanchor,
+    /// codec rebuild, surface recreate) so the gap across it is not scored as a stall.
+    pub fn split(&mut self) {
+        self.last_present_ns = 0;
+    }
+
+    /// Fold one on-glass instant. `period_ns` is the learned panel period
+    /// ([`PanelGrid::period_ns`]); a non-positive one means the grid is not known yet and the
+    /// sample is held as the new predecessor without being scored.
+    pub fn record(&mut self, present_ns: i64, period_ns: i64) {
+        let prev = std::mem::replace(&mut self.last_present_ns, present_ns);
+        if prev <= 0 || period_ns <= 0 {
+            return; // first sample of a run, or no grid to quantise against
+        }
+        let spacing = present_ns - prev;
+        if spacing <= 0 {
+            // A repeated or out-of-order callback. Hold the LATER instant so one reordered
+            // delivery cannot corrupt every following spacing — but only when the step back is
+            // small enough to BE a reordering. Beyond that the old instant is the bogus one
+            // (see [`CADENCE_REANCHOR_NS`]) and the run re-anchors onto the new sample, which
+            // `last_present_ns` already holds.
+            self.disordered += 1;
+            if prev - present_ns < CADENCE_REANCHOR_NS {
+                self.last_present_ns = prev;
+            }
+            return;
+        }
+        // Round to the nearest whole refresh: a present is "on the grid" if it is closer to this
+        // vblank than the next, which is exactly what the display did with it.
+        let units = (spacing * 2 + period_ns) / (period_ns * 2);
+        if units as usize > CADENCE_MAX_UNITS {
+            self.stalls += 1;
+            return;
+        }
+        self.hist[units as usize] += 1;
+        self.samples += 1;
+    }
+
+    /// The window's raw counts `(samples, stalls, disordered)`, whatever the evidence bar.
+    ///
+    /// [`summary`](Self::summary) returning `None` is otherwise indistinguishable from a window
+    /// of perfectly smooth zeros in a log line, which makes "no cadence is being scored at all"
+    /// invisible — the exact failure this exists to diagnose.
+    pub fn pending(&self) -> (u32, u32, u32) {
+        (self.samples, self.stalls, self.disordered)
+    }
+
+    /// This window's summary, or `None` under [`CADENCE_MIN_SAMPLES`].
+    pub fn summary(&self) -> Option<PresentCadence> {
+        if self.samples < CADENCE_MIN_SAMPLES {
+            return None;
+        }
+        // Ties resolve to the SMALLEST spacing, spelled out rather than left to a library:
+        // `max_by_key` would take the last maximum and Swift's `max(by:)` the first, so a
+        // 50/50 window (the classic 1-and-3 sawtooth) would label its mode differently on
+        // Android and Apple while reporting the same judder. The clients have to agree.
+        let mut mode_units = 0u8;
+        let mut mode_count = 0u32;
+        for (i, &c) in self.hist.iter().enumerate() {
+            if c > mode_count {
+                mode_count = c;
+                mode_units = i as u8;
+            }
+        }
+        Some(PresentCadence {
+            mode_units,
+            judder_permille: (u64::from(self.samples - mode_count) * 1000 / u64::from(self.samples))
+                as u16,
+            samples: self.samples,
+            stalls: self.stalls,
+            disordered: self.disordered,
+        })
+    }
+
+    /// Drain the window: the summary (if it clears the evidence bar) and a reset of the counts.
+    /// The previous instant SURVIVES the drain — the cadence continues across a window boundary,
+    /// and dropping it would manufacture one unscored interval per window.
+    pub fn take(&mut self) -> Option<PresentCadence> {
+        let out = self.summary();
+        self.hist = [0; CADENCE_MAX_UNITS + 1];
+        self.samples = 0;
+        self.stalls = 0;
+        self.disordered = 0;
+        out
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -294,3 +455,178 @@ mod panel_grid_tests {
         assert_eq!(g.period_ns(), P120, "and the real grid wins it back");
     }
 }
+
+#[cfg(test)]
+mod cadence_tests {
+    use super::*;
+
+    const P: i64 = 8_333_333; // 120 Hz in ns
+
+    /// Fold `n` presents spaced by `spacings` in rotation, starting at an arbitrary instant.
+    fn cadence(spacings: &[i64], n: usize) -> PresentIntervals {
+        let mut pi = PresentIntervals::new();
+        let mut t = 1_000_000_000i64;
+        pi.record(t, P);
+        for i in 0..n {
+            t += spacings[i % spacings.len()];
+            pi.record(t, P);
+        }
+        pi
+    }
+
+    #[test]
+    fn a_regular_cadence_has_no_judder() {
+        let s = cadence(&[P], 60).summary().unwrap();
+        assert_eq!((s.mode_units, s.judder_permille), (1, 0));
+        assert_eq!(s.samples, 60);
+    }
+
+    /// The property that makes this one ruler across rates: a stream at half the panel rate is
+    /// SMOOTH, not judder — the mode absorbs the cadence ratio.
+    fn ratio_is_absorbed_not_penalised(mult: i64, expect_units: u8) {
+        let s = cadence(&[P * mult], 40).summary().unwrap();
+        assert_eq!((s.mode_units, s.judder_permille), (expect_units, 0));
+    }
+
+    #[test]
+    fn sixty_on_onetwenty_reads_smooth() {
+        ratio_is_absorbed_not_penalised(2, 2); // 60 fps on a 120 Hz panel
+        ratio_is_absorbed_not_penalised(4, 4); // 30 fps on a 120 Hz panel
+    }
+
+    /// D3's signature: the same mean spacing as `sixty_on_onetwenty_reads_smooth`, delivered as
+    /// alternating 1 and 3 refreshes. Identical average frame rate, identical latency
+    /// percentiles — and this is the one that looks broken.
+    #[test]
+    fn the_sawtooth_that_latency_stats_cannot_see() {
+        let s = cadence(&[P, P * 3], 40).summary().unwrap();
+        assert_eq!(s.judder_permille, 500);
+        assert_eq!(
+            s.mode_units, 1,
+            "a tied mode resolves to the smallest spacing — pinned so the Swift port agrees"
+        );
+    }
+
+    /// Sub-refresh jitter is not judder: the display quantises it away, so the metric must too.
+    /// Only a spacing that crosses the half-refresh boundary changes which vblank was used.
+    #[test]
+    fn jitter_inside_a_refresh_is_not_judder() {
+        let s = cadence(&[P + P * 2 / 5, P - P * 2 / 5], 40)
+            .summary()
+            .unwrap();
+        assert_eq!((s.mode_units, s.judder_permille), (1, 0));
+    }
+
+    #[test]
+    fn a_stall_is_counted_apart_from_judder() {
+        let mut pi = PresentIntervals::new();
+        let mut t = 1_000_000_000i64;
+        pi.record(t, P);
+        for _ in 0..20 {
+            t += P;
+            pi.record(t, P);
+        }
+        t += P * 400; // a pause, not a pacing defect
+        pi.record(t, P);
+        let s = pi.summary().unwrap();
+        assert_eq!((s.judder_permille, s.stalls, s.samples), (0, 1, 20));
+    }
+
+    #[test]
+    fn out_of_order_callbacks_do_not_corrupt_the_run() {
+        let mut pi = PresentIntervals::new();
+        let mut t = 1_000_000_000i64;
+        pi.record(t, P);
+        for _ in 0..10 {
+            t += P;
+            pi.record(t, P);
+        }
+        pi.record(t - P * 3, P); // a late/duplicate delivery
+        for _ in 0..10 {
+            t += P;
+            pi.record(t, P);
+        }
+        let s = pi.summary().unwrap();
+        assert_eq!(s.disordered, 1);
+        assert_eq!(
+            s.judder_permille, 0,
+            "keeping the later instant means the following spacings stay on the grid"
+        );
+    }
+
+    /// The on-glass failure of 2026-08-05, pinned. Android's render callback can deliver a
+    /// garbage far-future timestamp on a session's first frames. Holding "the later instant"
+    /// unconditionally latched onto it and scored EVERY subsequent present as disordered —
+    /// `cadN=0 disorder=119` per second, for the whole session, with the period known and the
+    /// stream perfectly healthy. One bad sample must cost one sample, not the session.
+    #[test]
+    fn a_garbage_far_future_stamp_does_not_wedge_the_run() {
+        let mut pi = PresentIntervals::new();
+        let mut t = 1_000_000_000i64;
+        pi.record(t, P);
+        pi.record(t + 60 * 60 * 1_000_000_000, P); // a vendor's epoch-sized first stamp
+        for _ in 0..20 {
+            t += P;
+            pi.record(t, P);
+        }
+        let s = pi.summary().expect("the run recovers instead of wedging");
+        assert_eq!(s.disordered, 1, "the garbage stamp cost exactly one sample");
+        assert_eq!((s.mode_units, s.judder_permille), (1, 0));
+        assert_eq!(s.samples, 19, "every present after the re-anchor scored");
+    }
+
+    #[test]
+    fn an_unknown_grid_scores_nothing() {
+        let s = cadence(&[P], 60);
+        let mut pi = PresentIntervals::new();
+        let mut t = 1_000_000_000i64;
+        for _ in 0..60 {
+            t += P;
+            pi.record(t, 0); // PanelGrid has not learned a period yet
+        }
+        assert!(pi.summary().is_none());
+        assert!(s.summary().is_some(), "control");
+    }
+
+    #[test]
+    fn a_short_window_publishes_nothing() {
+        assert!(cadence(&[P], 5).summary().is_none());
+    }
+
+    /// The cadence continues across a window boundary — dropping the predecessor on drain would
+    /// silently discard one interval per window, every window.
+    #[test]
+    fn take_resets_the_counts_but_not_the_cadence() {
+        let mut pi = cadence(&[P], 20);
+        assert!(pi.take().is_some());
+        assert!(pi.summary().is_none(), "counts cleared");
+        let mut t = 1_000_000_000 + P * 20;
+        for _ in 0..10 {
+            t += P;
+            pi.record(t, P);
+        }
+        let s = pi.summary().unwrap();
+        assert_eq!(
+            s.samples, 10,
+            "the first post-drain present scored against the pre-drain one"
+        );
+    }
+
+    #[test]
+    fn split_forgets_the_predecessor() {
+        let mut pi = cadence(&[P], 20);
+        pi.take();
+        pi.split();
+        let mut t = 5_000_000_000i64; // a reanchor: the gap across it is meaningless
+        for _ in 0..10 {
+            t += P;
+            pi.record(t, P);
+        }
+        let s = pi.summary().unwrap();
+        assert_eq!(
+            (s.samples, s.stalls),
+            (9, 0),
+            "the gap was not scored at all"
+        );
+    }
+}

crates/punktfunk-core/src/quic/caps.rs

@@ -121,6 +121,15 @@ pub const CLIENT_CAP_PHASE_LOCK: u8 = 0x02;
 /// clean, the client keeps receiving the plain `0xC9` plane — so a client may always set this bit.
 /// `0x04` — `0x01`/`0x02` are cursor / phase-lock.
 pub const CLIENT_CAP_AUDIO_RED: u8 = 0x04;
+/// [`Hello::client_caps`] bit: the client understands the pad-audio plane
+/// ([`PAD_AUDIO_MAGIC`](super::datagram::PAD_AUDIO_MAGIC), `0xD1`) — per-gamepad DualSense
+/// voice-coil haptics + speaker Opus frames, plus the [`HidOutput::AudioCtl`]
+/// (super::datagram::HidOutput) routing/volume events. Active only when the host answers with
+/// [`HOST_CAP_PAD_AUDIO`] AND the pad's arrival declared a renderer for the kind
+/// ([`crate::input::ARRIVAL_FLAG_PAD_AUDIO_HAPTICS`]/`_SPEAKER`) — the capable-and-agreed
+/// precedent, per pad; toward an older or incapable host nothing changes. `0x08` — `0x01` is [`CLIENT_CAP_CURSOR`],
+/// `0x02` is [`CLIENT_CAP_PHASE_LOCK`], `0x04` is [`CLIENT_CAP_AUDIO_RED`].
+pub const CLIENT_CAP_PAD_AUDIO: u8 = 0x08;
 
 /// [`Welcome::host_caps`] bit: the host CAN forward the cursor out-of-band (it captures cursor
 /// metadata separately from the frame — the Linux portal `SPA_META_Cursor` path; NOT gamescope,
@@ -154,6 +163,16 @@ pub const HOST_CAP_PEN: u8 = 0x10;
 /// unconditionally and treat this bit as "expect redundancy", not "only redundancy".
 /// `0x20` — `0x10` is [`HOST_CAP_PEN`], `0x08` is [`HOST_CAP_CURSOR`].
 pub const HOST_CAP_AUDIO_RED: u8 = 0x20;
+/// [`Welcome::host_caps`] bit: the host can capture pad audio — its virtual DualSense exposes
+/// the pad's audio endpoints (voice-coil haptics + speaker), so a game's per-pad audio can be
+/// captured and shipped on the [`PAD_AUDIO_MAGIC`](super::datagram::PAD_AUDIO_MAGIC) plane.
+/// Set only when the client asked via [`CLIENT_CAP_PAD_AUDIO`]; when both bits agree, a
+/// capable client marks its pads' render capabilities on their arrivals
+/// ([`crate::input::ARRIVAL_FLAG_PAD_AUDIO_HAPTICS`]/`_SPEAKER`) and the host emits `0xD1`
+/// toward exactly those pads. `0x40` — `0x20` is [`HOST_CAP_AUDIO_RED`], `0x10` is
+/// [`HOST_CAP_PEN`], `0x08` is [`HOST_CAP_CURSOR`], `0x04` is [`HOST_CAP_TEXT_INPUT`],
+/// `0x01`/`0x02` are gamepad-state / clipboard.
+pub const HOST_CAP_PAD_AUDIO: u8 = 0x40;
 
 /// [`Hello::video_codecs`] bit: the client can decode H.264 / AVC. The GPU-less **software**
 /// encode path (openh264) emits H.264, so a client that wants to stream from a software host MUST
@@ -337,6 +356,28 @@ mod tests {
         );
     }
 
+    #[test]
+    fn pad_audio_cap_bits_are_distinct() {
+        // The new pad-audio bits pack into the existing caps bytes without colliding with any
+        // taken bit (a collision would silently negotiate an unrelated feature).
+        assert_eq!(
+            CLIENT_CAP_PAD_AUDIO & (CLIENT_CAP_CURSOR | CLIENT_CAP_PHASE_LOCK),
+            0
+        );
+        assert_eq!(
+            HOST_CAP_PAD_AUDIO
+                & (HOST_CAP_GAMEPAD_STATE
+                    | HOST_CAP_CLIPBOARD
+                    | HOST_CAP_TEXT_INPUT
+                    | HOST_CAP_CURSOR
+                    | HOST_CAP_PEN),
+            0
+        );
+        // Single-bit values (a multi-bit cap would OR neighbours in).
+        assert_eq!(CLIENT_CAP_PAD_AUDIO.count_ones(), 1);
+        assert_eq!(HOST_CAP_PAD_AUDIO.count_ones(), 1);
+    }
+
     #[test]
     fn resolve_codec_canonicalizes_a_multi_bit_preference() {
         // A non-conformant peer may stuff its capability MASK into `preferred` — the result

crates/punktfunk-core/src/quic/datagram.rs

@@ -1,12 +1,15 @@
-//! The QUIC-datagram side planes, demultiplexed by their first byte (0xC9–0xCF):
-//! audio, rumble, mic uplink, rich input, HID output, HDR metadata, host timing.
+//! The QUIC-datagram side planes, demultiplexed by their first byte (0xC9–0xD1):
+//! audio, rumble, mic uplink, rich input, HID output, HDR metadata, host timing,
+//! cursor state, pad audio.
 
 /// Datagram wire tags. Video rides UDP; everything low-rate rides QUIC datagrams,
 /// demultiplexed by the first byte: input = [`crate::input::INPUT_MAGIC`] (0xC8, client→host),
 /// audio = [`AUDIO_MAGIC`] (0xC9, host→client), rumble = [`RUMBLE_MAGIC`] (0xCA, host→client),
 /// mic = [`MIC_MAGIC`] (0xCB, client→host), rich-input = [`RICH_INPUT_MAGIC`] (0xCC, client→host),
 /// HID-output = [`HIDOUT_MAGIC`] (0xCD, host→client), HDR metadata = [`HDR_META_MAGIC`]
-/// (0xCE, host→client).
+/// (0xCE, host→client), host timing = [`HOST_TIMING_MAGIC`] (0xCF, host→client), cursor state =
+/// [`CURSOR_STATE_MAGIC`] (0xD0, host→client), pad audio = [`PAD_AUDIO_MAGIC`] (0xD1,
+/// host→client).
 pub const AUDIO_MAGIC: u8 = 0xC9;
 pub const RUMBLE_MAGIC: u8 = 0xCA;
 /// Microphone uplink: the client's mic, Opus-encoded, client → host (the inverse of
@@ -401,11 +404,22 @@ impl RichInput {
     }
 }
 
+/// Longest [`HidOutput::Trigger`] `effect` the wire carries: the DualSense adaptive-trigger
+/// parameter block is a mode byte plus ten parameters, and every consumer copies at most this many
+/// into its report.
+///
+/// The single source for the clamp on BOTH sides. `Trigger` was the only variable-length variant
+/// bounded on neither: encode appended whatever it was handed and decode took the entire tail, so
+/// an attacker-sized datagram was reproduced verbatim into a `Vec` while its sibling `HidRaw` had
+/// been bounded on both ends all along.
+pub const TRIGGER_EFFECT_MAX: usize = 11;
+
 const HIDOUT_LED: u8 = 0x01;
 const HIDOUT_PLAYER_LEDS: u8 = 0x02;
 const HIDOUT_TRIGGER: u8 = 0x03;
 const HIDOUT_TRACKPAD_HAPTIC: u8 = 0x04;
 const HIDOUT_HID_RAW: u8 = 0x05;
+const HIDOUT_AUDIO_CTL: u8 = 0x06;
 
 /// [`HidOutput::HidRaw`] `kind`: an OUTPUT report — what the host's hidraw client wrote with
 /// `write()`/`SDL_hid_write` (Triton rumble `0x80`, haptic pulse `0x81`, …). The client replays
@@ -431,6 +445,14 @@ pub enum HidOutput {
     /// A trackpad haptic pulse for a Steam Controller's voice-coil actuators (its only "rumble").
     /// `side` 0 = right pad, 1 = left pad; `amplitude` + `period` (µs off-time) + `count` (pulses)
     /// synthesize a buzz. A client without trackpad coils drops it (or maps it to ordinary rumble).
+    ///
+    /// **STAGED SCAFFOLDING — deliberately unreachable today, do not delete.** Nothing on the host
+    /// produces this variant and no client renders it; it codes/decodes and round-trips in tests
+    /// and nothing else. It stays because `HIDOUT_TRACKPAD_HAPTIC` is an allocated tag on a
+    /// SHIPPED wire: removing the variant would not reclaim the tag (a future peer could still
+    /// send it), it would only lose the decoder that keeps such a datagram from being mistaken
+    /// for something else. The producer is the Steam Controller coil path; the renderer is the
+    /// client-side coil write. Wire up either half and this becomes live with no format change.
     TrackpadHaptic {
         pad: u8,
         side: u8,
@@ -446,6 +468,16 @@ pub enum HidOutput {
     /// hardware safety timeout, and settings (lizard/IMU) are refreshed every ~3 s against the
     /// firmware watchdog — a lost datagram heals on the next refresh.
     HidRaw { pad: u8, kind: u8, data: Vec<u8> },
+    /// The audio-control region of a DS5 output report `0x02` a game wrote to the host's virtual
+    /// pad — the routing/volume side of pad audio (the audio SAMPLES ride the [`PAD_AUDIO_MAGIC`]
+    /// plane). `raw` is bytes 5..=10 of the report verbatim (headphone/speaker/mic volumes +
+    /// audio routing); `flags` condenses the report's audio valid-flags: bit0 = haptics-select
+    /// (`valid_flag0` bit1 — the title asked for audio haptics on the voice coils), bits1..4 =
+    /// `valid_flag0` bits 4..7 (the audio-valid flags gating `raw`). Wire form
+    /// `[0xCD][0x06][u16 pad LE][u8 flags][6 raw bytes]`. Forwarded change-only (deduped by
+    /// value host-side, like `Led`/`Trigger`) — a merely-rumbling pad re-sends unchanged audio
+    /// state on every output report.
+    AudioCtl { pad: u16, flags: u8, raw: [u8; 6] },
 }
 
 impl HidOutput {
@@ -460,7 +492,7 @@ impl HidOutput {
             }
             HidOutput::Trigger { pad, which, effect } => {
                 out.extend_from_slice(&[HIDOUT_TRIGGER, *pad, *which]);
-                out.extend_from_slice(effect);
+                out.extend_from_slice(&effect[..effect.len().min(TRIGGER_EFFECT_MAX)]);
             }
             HidOutput::TrackpadHaptic {
                 pad,
@@ -478,6 +510,12 @@ impl HidOutput {
                 out.extend_from_slice(&[HIDOUT_HID_RAW, *pad, *kind]);
                 out.extend_from_slice(&data[..data.len().min(HID_REPORT_MAX)]);
             }
+            HidOutput::AudioCtl { pad, flags, raw } => {
+                out.push(HIDOUT_AUDIO_CTL);
+                out.extend_from_slice(&pad.to_le_bytes());
+                out.push(*flags);
+                out.extend_from_slice(raw);
+            }
         }
         out
     }
@@ -497,10 +535,17 @@ impl HidOutput {
                 pad: b[2],
                 bits: b[3],
             }),
-            HIDOUT_TRIGGER if b.len() >= 4 => Some(HidOutput::Trigger {
+            // `> 4`, not `>= 4`: a body with no effect bytes at all is malformed, and decoding it
+            // as an EMPTY effect was actively harmful — downstream an empty block is written as an
+            // all-zero trigger report, which is mode 0x00, which RELEASES a held effect. A
+            // truncated datagram could therefore silently cancel the trigger a game was holding.
+            // A genuine "no effect" is a full-length zero block and still decodes fine.
+            HIDOUT_TRIGGER if b.len() > 4 => Some(HidOutput::Trigger {
                 pad: b[2],
                 which: b[3],
-                effect: b[4..].to_vec(),
+                // Bounded like `HidRaw` below: at most the parameter block is kept from the
+                // (attacker-sized) tail.
+                effect: b[4..b.len().min(4 + TRIGGER_EFFECT_MAX)].to_vec(),
             }),
             HIDOUT_TRACKPAD_HAPTIC if b.len() >= 10 => Some(HidOutput::TrackpadHaptic {
                 pad: b[2],
@@ -515,6 +560,22 @@ impl HidOutput {
                 // Bounded: at most HID_REPORT_MAX bytes are kept from the (attacker-sized) tail.
                 data: b[4..b.len().min(4 + HID_REPORT_MAX)].to_vec(),
             }),
+            // B27: the pad is the only u16 index on this plane, and every consumer narrows it
+            // with `as u8` on the stated assumption that pads are 0..MAX_PADS. Nothing enforced
+            // that, so wire pad 256 silently ALIASED onto slot 0 — a malformed or hostile
+            // datagram steering a real controller's speaker volumes. Rejected here, at the one
+            // place the u16 exists, so the narrowings downstream are lossless by construction
+            // (the same fix R10 applied to the rumble plane).
+            HIDOUT_AUDIO_CTL
+                if b.len() >= 11
+                    && u16::from_le_bytes([b[2], b[3]]) < crate::input::MAX_PADS as u16 =>
+            {
+                Some(HidOutput::AudioCtl {
+                    pad: u16::from_le_bytes([b[2], b[3]]),
+                    flags: b[4],
+                    raw: b[5..11].try_into().unwrap(),
+                })
+            }
             _ => None,
         }
     }
@@ -773,6 +834,72 @@ pub fn decode_cursor_state_datagram(b: &[u8]) -> Option<CursorState> {
     })
 }
 
+/// Pad-audio datagram tag, host → client: per-gamepad audio a game routed
+/// to the host's virtual DualSense — voice-coil haptics and the built-in speaker — for the client
+/// to render on the matching real controller. Next tag after [`CURSOR_STATE_MAGIC`]. The
+/// per-pad AUDIO plane (Opus frames, the [`AUDIO_MAGIC`]/[`MIC_MAGIC`] shape plus pad + kind);
+/// the routing/volume CONTROL side rides [`HidOutput::AudioCtl`]. Emitted only when the session
+/// negotiated it ([`CLIENT_CAP_PAD_AUDIO`](super::caps::CLIENT_CAP_PAD_AUDIO) ∧
+/// [`HOST_CAP_PAD_AUDIO`](super::caps::HOST_CAP_PAD_AUDIO)) and the pad's arrival declared a
+/// renderer for the kind ([`crate::input::ARRIVAL_FLAG_PAD_AUDIO_HAPTICS`]/`_SPEAKER`).
+/// Best-effort like every audio datagram: a lost frame is a concealed gap, never state.
+pub const PAD_AUDIO_MAGIC: u8 = 0xD1;
+
+/// [`PadAudioFrame::kind`]: the BACK channel pair — the DualSense voice-coil actuators (audio
+/// haptics). 5 ms Opus frames, matching the [`AUDIO_MAGIC`] cadence: haptics are felt latency.
+pub const PAD_AUDIO_KIND_HAPTICS: u8 = 0;
+/// [`PadAudioFrame::kind`]: the FRONT channel pair — the controller's built-in speaker. 10 ms
+/// Opus frames (speaker content tolerates the extra buffering for the better coding efficiency).
+pub const PAD_AUDIO_KIND_SPEAKER: u8 = 1;
+
+/// Wire length of a pad-audio datagram header: tag + pad + kind + u32 seq + u64 pts = 15 bytes.
+const PAD_AUDIO_HEADER_LEN: usize = 1 + 1 + 1 + 4 + 8;
+
+/// One decoded pad-audio frame (owned — the client's plane queue stores it). `seq`/`pts_ns` are
+/// per-(pad, kind) counters from the host's capture clock, for gap concealment and lip-sync
+/// against the main audio plane.
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct PadAudioFrame {
+    /// Gamepad index (the wire pad space, same as rumble/HID-output).
+    pub pad: u8,
+    /// [`PAD_AUDIO_KIND_HAPTICS`] or [`PAD_AUDIO_KIND_SPEAKER`].
+    pub kind: u8,
+    pub seq: u32,
+    pub pts_ns: u64,
+    /// The raw Opus payload — feed it to an Opus decoder as one frame. Empty = DTX silence.
+    pub opus: Vec<u8>,
+}
+
+/// Pad-audio datagram, host → client:
+/// `[0xD1][u8 pad][u8 kind][u32 seq LE][u64 pts_ns LE][opus payload]` — the
+/// [`encode_audio_datagram`]/[`encode_mic_datagram`] layout with a pad + kind prefix, one Opus
+/// frame per datagram (5/10 ms — well under any MTU); QUIC already encrypts.
+pub fn encode_pad_audio_datagram(pad: u8, kind: u8, seq: u32, pts_ns: u64, opus: &[u8]) -> Vec<u8> {
+    let mut b = Vec::with_capacity(PAD_AUDIO_HEADER_LEN + opus.len());
+    b.push(PAD_AUDIO_MAGIC);
+    b.push(pad);
+    b.push(kind);
+    b.extend_from_slice(&seq.to_le_bytes());
+    b.extend_from_slice(&pts_ns.to_le_bytes());
+    b.extend_from_slice(opus);
+    b
+}
+
+/// Parse a pad-audio datagram → [`PadAudioFrame`]. `None` on bad tag/length (the fixed header
+/// length bounds every read before it happens).
+pub fn decode_pad_audio_datagram(buf: &[u8]) -> Option<PadAudioFrame> {
+    if buf.len() < PAD_AUDIO_HEADER_LEN || buf[0] != PAD_AUDIO_MAGIC {
+        return None;
+    }
+    Some(PadAudioFrame {
+        pad: buf[1],
+        kind: buf[2],
+        seq: u32::from_le_bytes(buf[3..7].try_into().unwrap()),
+        pts_ns: u64::from_le_bytes(buf[7..15].try_into().unwrap()),
+        opus: buf[15..].to_vec(),
+    })
+}
+
 #[cfg(test)]
 mod tests {
     use crate::quic::*;
@@ -981,6 +1108,82 @@ mod tests {
         assert!(decode_rumble_datagram(&d[..6]).is_none());
     }
 
+    /// `Trigger` is the only variable-length variant that used to be bounded on NEITHER side.
+    /// Pinned here because both halves matter: an over-long effect must be clamped on the way out
+    /// AND on the way in, and a body with no effect bytes must not decode at all.
+    #[test]
+    fn trigger_effect_is_clamped_on_both_encode_and_decode() {
+        // Encode clamps: a caller handing over an over-long block cannot put it on the wire.
+        let long = HidOutput::Trigger {
+            pad: 1,
+            which: 0,
+            effect: vec![0xAB; 200],
+        };
+        let d = long.encode();
+        assert_eq!(
+            d.len(),
+            4 + TRIGGER_EFFECT_MAX,
+            "magic + kind + pad + which + at most the parameter block"
+        );
+
+        // Decode clamps independently of encode — a hostile peer does not use our encoder.
+        let mut hostile = vec![HIDOUT_MAGIC, super::HIDOUT_TRIGGER, 1, 0];
+        hostile.extend_from_slice(&[0xCD; 500]);
+        match HidOutput::decode(&hostile) {
+            Some(HidOutput::Trigger { effect, .. }) => {
+                assert_eq!(effect.len(), TRIGGER_EFFECT_MAX, "tail is bounded");
+            }
+            other => panic!("expected a clamped Trigger, got {other:?}"),
+        }
+
+        // An exact-length effect survives untouched, and round-trips.
+        let ok = HidOutput::Trigger {
+            pad: 2,
+            which: 1,
+            effect: vec![0x02, 0x90, 0xA0, 0xFF, 0, 0, 0, 0, 0, 0, 0],
+        };
+        assert_eq!(HidOutput::decode(&ok.encode()), Some(ok));
+    }
+
+    /// A body with no effect bytes is malformed and must be REJECTED, not read as an empty effect:
+    /// downstream an empty block becomes an all-zero trigger report, which is mode 0x00 — it
+    /// releases whatever effect the game was holding. A truncated datagram must not do that.
+    #[test]
+    fn a_trigger_with_no_effect_bytes_is_rejected_not_read_as_cancel() {
+        let empty = [HIDOUT_MAGIC, super::HIDOUT_TRIGGER, 0, 0];
+        assert_eq!(HidOutput::decode(&empty), None);
+
+        // One byte of effect is a legitimate short block (consumers zero-pad it) and still decodes.
+        let one = [HIDOUT_MAGIC, super::HIDOUT_TRIGGER, 0, 0, 0x02];
+        assert_eq!(
+            HidOutput::decode(&one),
+            Some(HidOutput::Trigger {
+                pad: 0,
+                which: 0,
+                effect: vec![0x02]
+            })
+        );
+    }
+
+    /// `HidRaw`'s bound was already correct on both sides — pinned alongside `Trigger` so the pair
+    /// cannot drift apart again.
+    #[test]
+    fn hid_raw_stays_bounded_on_both_sides() {
+        let long = HidOutput::HidRaw {
+            pad: 0,
+            kind: HID_RAW_OUTPUT,
+            data: vec![0x11; 500],
+        };
+        assert_eq!(long.encode().len(), 4 + HID_REPORT_MAX);
+
+        let mut hostile = vec![HIDOUT_MAGIC, super::HIDOUT_HID_RAW, 0, HID_RAW_FEATURE];
+        hostile.extend_from_slice(&[0x22; 900]);
+        match HidOutput::decode(&hostile) {
+            Some(HidOutput::HidRaw { data, .. }) => assert_eq!(data.len(), HID_REPORT_MAX),
+            other => panic!("expected a clamped HidRaw, got {other:?}"),
+        }
+    }
+
     #[test]
     fn rumble_envelope_roundtrip_and_legacy_tolerance() {
         // v2 envelope round-trips seq + ttl.
@@ -1180,6 +1383,12 @@ mod tests {
                     f
                 },
             },
+            // The DS5 audio-control region (haptics-select + speaker volume asserted).
+            HidOutput::AudioCtl {
+                pad: 1,
+                flags: 0b0_0101,
+                raw: [0x50, 0x60, 0x70, 0x05, 0x00, 0x00],
+            },
         ];
         for ev in &cases {
             let d = ev.encode();
@@ -1198,6 +1407,92 @@ mod tests {
         )
         .is_none());
     }
+
+    #[test]
+    fn audio_ctl_wire_layout_and_truncation() {
+        // The exact 11-byte layout: [0xCD][0x06][u16 pad LE][u8 flags][6 raw bytes].
+        // The pad is deliberately a REPRESENTABLE one: this used to assert that 0x0201 (513)
+        // round-tripped, which pinned B27's aliasing in place as if it were the contract.
+        let a = HidOutput::AudioCtl {
+            pad: 0x000B,
+            flags: 0x17,
+            raw: [1, 2, 3, 4, 5, 6],
+        };
+        let d = a.encode();
+        assert_eq!(d, [0xCD, 0x06, 0x0B, 0x00, 0x17, 1, 2, 3, 4, 5, 6]);
+        assert_eq!(HidOutput::decode(&d), Some(a));
+        // Truncated buffers are rejected outright (fixed length — never a partial read).
+        for n in 2..d.len() {
+            assert_eq!(HidOutput::decode(&d[..n]), None);
+        }
+    }
+
+    #[test]
+    fn pad_audio_datagram_roundtrip_and_truncation() {
+        let opus = [0x5Au8; 61];
+        let d = encode_pad_audio_datagram(3, PAD_AUDIO_KIND_HAPTICS, 42, 9_999, &opus);
+        assert_eq!(d[0], PAD_AUDIO_MAGIC);
+        assert_eq!(d.len(), 15 + opus.len());
+        let f = decode_pad_audio_datagram(&d).unwrap();
+        assert_eq!((f.pad, f.kind, f.seq, f.pts_ns), (3, 0, 42, 9_999));
+        assert_eq!(f.opus, opus);
+        // Truncated headers are rejected outright (never partially read).
+        for n in 0..15 {
+            assert_eq!(decode_pad_audio_datagram(&d[..n]), None);
+        }
+        // Tag separation: a pad-audio datagram is not a session-audio/mic datagram and vice-versa.
+        assert!(decode_audio_datagram(&d).is_none());
+        assert!(decode_mic_datagram(&d).is_none());
+        assert!(decode_pad_audio_datagram(&encode_audio_datagram(1, 2, &opus)).is_none());
+        // Empty payload (DTX) is legal — header-only datagram.
+        let hdr = encode_pad_audio_datagram(0, PAD_AUDIO_KIND_SPEAKER, 0, 0, &[]);
+        assert_eq!(hdr.len(), 15);
+        assert!(decode_pad_audio_datagram(&hdr).unwrap().opus.is_empty());
+    }
+
+    /// B27: the pad is the only u16 index on the 0xCD plane and every consumer narrows it with
+    /// `as u8`. An out-of-range one used to alias onto a real slot instead of being refused —
+    /// wire pad 256 steering pad 0's speaker volumes.
+    #[test]
+    fn audio_ctl_rejects_a_pad_outside_the_index_space() {
+        let ok = HidOutput::AudioCtl {
+            pad: (crate::input::MAX_PADS - 1) as u16,
+            flags: 0x12,
+            raw: [1, 2, 3, 4, 5, 6],
+        };
+        assert_eq!(
+            HidOutput::decode(&ok.encode()),
+            Some(ok),
+            "the last valid pad must still decode"
+        );
+
+        // Anything at or above MAX_PADS is refused outright, not truncated.
+        for pad in [crate::input::MAX_PADS as u16, 256, u16::MAX] {
+            let d = HidOutput::AudioCtl {
+                pad,
+                flags: 0x12,
+                raw: [1, 2, 3, 4, 5, 6],
+            }
+            .encode();
+            assert_eq!(HidOutput::decode(&d), None, "pad {pad} must not decode");
+        }
+
+        // The specific alias the bug produced: 256 as u8 == 0.
+        let d = HidOutput::AudioCtl {
+            pad: 256,
+            flags: 0,
+            raw: [0; 6],
+        }
+        .encode();
+        assert!(
+            !matches!(
+                HidOutput::decode(&d),
+                Some(HidOutput::AudioCtl { pad: 0, .. })
+            ),
+            "wire pad 256 must never surface as pad 0"
+        );
+    }
+
     #[test]
     fn cursor_state_roundtrip() {
         for (flags, x, y) in [

crates/punktfunk-core/src/quic/mod.rs

@@ -25,7 +25,7 @@
 //! Split by concern (networking-audit deferred plan §3 — a pure move): `handshake` the
 //! positional Hello/Welcome/Start codecs, `caps` the capability/codec-negotiation
 //! vocabulary, `control` the typed control + clipboard messages, `pairing` the pairing
-//! message codecs with [`pake`] the SPAKE2 itself, `datagram` the 0xC9–0xCF plane codecs,
+//! message codecs with [`pake`] the SPAKE2 itself, `datagram` the 0xC9–0xD1 plane codecs,
 //! `pen` the stylus batch (0xCC kind 0x05) + host stroke tracker,
 //! [`io`] framed stream IO, `clock` skew estimation + mid-stream re-sync, [`endpoint`] the
 //! quinn constructors, [`clipstream`] the per-transfer clipboard fetch streams. Every item

crates/punktfunk-host/Cargo.toml

@@ -259,6 +259,17 @@ windows = { version = "0.62", features = [
     # CoCreateInstance(PolicyConfigClient) — set the default audio playback/recording endpoints via the
     # undocumented IPolicyConfig (audio/windows/audio_control.rs) so mic + desktop audio auto-wire.
     "Win32_System_Com",
+    # Pad-audio endpoint provisioning (audio/windows/pad_endpoint.rs): IMMDevice + IPropertyStore
+    # to stamp the DualSense identity onto the minted endpoints (PROPVARIANT lives in
+    # StructuredStorage and is gated on the Variant feature), DEVPKEY_Device_DriverInfPath to
+    # resolve the installed Steam Streaming Speakers INF, and raw Reg* calls behind the MMDevices
+    # ACL repair + the devnode's pad-index marker value.
+    "Win32_Media_Audio",
+    "Win32_UI_Shell_PropertiesSystem",
+    "Win32_System_Com_StructuredStorage",
+    "Win32_System_Variant",
+    "Win32_Devices_Properties",
+    "Win32_System_Registry",
     # SetUnhandledExceptionFilter + EXCEPTION_POINTERS — the last-resort native-crash logger
     # (src/windows/crash.rs); Kernel gates the CONTEXT type EXCEPTION_POINTERS embeds.
     "Win32_System_Diagnostics_Debug",

crates/punktfunk-host/src/audio.rs

@@ -183,6 +183,12 @@ pub fn open_virtual_mic(_channels: u32) -> Result<Box<dyn VirtualMic>> {
 mod audio_control;
 #[cfg(target_os = "linux")]
 mod linux;
+// DualSense pad-audio endpoint provisioning + loopback capture (design: pad haptics/audio).
+// pub(crate): the session layer queries endpoints by pad index and the CLI exposes the
+// `pad-endpoint` devtest.
+#[cfg(target_os = "windows")]
+#[path = "audio/windows/pad_endpoint.rs"]
+pub(crate) mod pad_endpoint;
 #[cfg(target_os = "windows")]
 #[path = "audio/windows/wasapi_cap.rs"]
 mod wasapi_cap;

crates/punktfunk-host/src/audio/windows/audio_control.rs

@@ -143,6 +143,17 @@ pub(crate) fn wire_now(set_playback: bool) -> Wiring {
     wire_now_full(set_playback).wiring
 }
 
+/// Endpoint ids among `renders` that are the host's own pad-audio endpoints — the exclusion
+/// data [`plan`] runs on. Detection lives in [`super::pad_endpoint`] (stamped PFDS container /
+/// devnode marker, registry-only reads); this is just the per-pass collection.
+fn pad_render_ids(renders: &[Endpoint]) -> Vec<String> {
+    renders
+        .iter()
+        .filter(|(_, id)| super::pad_endpoint::is_pad_render_endpoint(id))
+        .map(|(_, id)| id.clone())
+        .collect()
+}
+
 /// Enumerate endpoints, compute the assignment, apply the default-device changes (unless
 /// `PUNKTFUNK_KEEP_DEFAULT`), and return the plan for the caller to act on (mic target / loopback
 /// echo guard). `set_playback` — true only from the desktop-audio capture open — additionally
@@ -159,6 +170,10 @@ pub(crate) fn wire_now_full(set_playback: bool) -> WiredPlan {
     let want = std::env::var("PUNKTFUNK_MIC_DEVICE")
         .ok()
         .map(|s| s.to_lowercase());
+    // The host's own pad-audio ("DualSense speaker") endpoints, by id — the pure plan filters
+    // them out of every role. Identity is platform data (stamped container / devnode marker),
+    // so it is collected HERE and passed in, like the candidate lists themselves.
+    let pad_ids = pad_render_ids(&renders);
     // Mix formats are read only when we are actually going to park the playback default (i.e. a
     // desktop-audio capture is opening). The mic pump wires on every open while the host is idle
     // and does not care which loopback endpoint wins, so it must not pay an IAudioClient
@@ -179,6 +194,7 @@ pub(crate) fn wire_now_full(set_playback: bool) -> WiredPlan {
         // only count a *narrowing* verdict can be made against without guessing: an endpoint that
         // cannot carry stereo cannot carry 5.1 either.
         2,
+        &pad_ids,
     );
     let done = |wiring: Wiring| WiredPlan {
         wiring,
@@ -245,7 +261,7 @@ pub(crate) fn wire_now_full(set_playback: bool) -> WiredPlan {
     if let Some((mic_name, mic_id)) = &wiring.mic_render {
         if default_render_id().as_deref() == Some(mic_id.as_str()) {
             // Audible preference = the host_audio plan's loopback pick (real hardware first).
-            match plan(&renders, &captures, want.as_deref(), true).loopback_render {
+            match plan(&renders, &captures, want.as_deref(), true, &pad_ids).loopback_render {
                 Some((name, id)) => match set_default_endpoint(&id) {
                     Ok(()) => tracing::info!(mic = %mic_name, device = %name,
                         "default playback was the virtual-mic target — moved it so desktop \
@@ -302,8 +318,10 @@ fn park_marker_path() -> std::path::PathBuf {
     pf_paths::config_dir().join("audio-default.prev")
 }
 
-/// The current default RENDER endpoint id, if any.
-fn default_render_id() -> Option<String> {
+/// The current default RENDER endpoint id, if any. pub(crate): the pad-endpoint provisioning
+/// uses it for its default-device guard (a freshly minted pad endpoint must never stay the
+/// default playback device).
+pub(crate) fn default_render_id() -> Option<String> {
     wasapi::DeviceEnumerator::new()
         .ok()?
         .get_default_device(&Direction::Render)
@@ -430,11 +448,13 @@ pub(crate) fn restore_default_playback() {
 }
 
 /// Open a device by endpoint id, with a name for error context.
+///
+/// Resolves through [`super::pad_endpoint::open_wasapi_device`], NOT the `wasapi` crate's
+/// `DeviceEnumerator::get_device` — that one hands `GetDevice` a freed string (see the helper's
+/// docs), so it fails at random on ids that are perfectly valid.
 pub(crate) fn open_endpoint(ep: &Endpoint) -> Result<wasapi::Device> {
-    wasapi::DeviceEnumerator::new()
-        .map_err(|e| anyhow!("DeviceEnumerator: {e}"))?
-        .get_device(&ep.1)
-        .map_err(|e| anyhow!("open endpoint {:?}: {e}", ep.0))
+    super::pad_endpoint::open_wasapi_device(&ep.1)
+        .map_err(|e| anyhow!("open endpoint {:?}: {e:#}", ep.0))
 }
 
 // --- IPolicyConfig (undocumented): set a default audio endpoint by id, for all three roles. ---
@@ -481,8 +501,9 @@ const _: () = {
 
 /// Set `device_id` as the default audio endpoint for eConsole/eMultimedia/eCommunications via the
 /// undocumented `IPolicyConfig::SetDefaultEndpoint` (the call `mmsys.cpl` makes). Errs if any role
-/// fails.
-fn set_default_endpoint(device_id: &str) -> Result<()> {
+/// fails. pub(crate): the pad-endpoint default-device guard restores the operator's default
+/// through the same machinery.
+pub(crate) fn set_default_endpoint(device_id: &str) -> Result<()> {
     use windows::core::{IUnknown, Interface, GUID, PCWSTR};
     use windows::Win32::System::Com::{CoCreateInstance, CLSCTX_ALL};
 

crates/punktfunk-host/src/audio/windows/wasapi_cap.rs

@@ -511,7 +511,7 @@ fn capture_once(
     if assert_plan {
         if let Some(d) = seen_default.as_deref() {
             if d != dev_id {
-                match judge_default(&en, wiring, d) {
+                match judge_default(wiring, d) {
                     DefaultKind::Capturable(name) => {
                         tracing::info!(default = %name, planned = %dev_name,
                             "could not park the default playback on the planned endpoint — \
@@ -639,7 +639,7 @@ fn capture_once(
                             );
                             return Ok(Next::Reopen(TargetMode::Follow));
                         }
-                        match judge_default(&en, wiring, &nid) {
+                        match judge_default(wiring, &nid) {
                             DefaultKind::Capturable(name) => {
                                 audio_client.stop_stream().ok();
                                 tracing::info!(device = %name,
@@ -726,8 +726,11 @@ enum DefaultKind {
     Unknown,
 }
 
-fn judge_default(en: &DeviceEnumerator, wiring: &wiring_plan::Wiring, id: &str) -> DefaultKind {
-    let Ok(dev) = en.get_device(id) else {
+/// Resolves through [`super::pad_endpoint::open_wasapi_device`], NOT the `wasapi` crate's
+/// `DeviceEnumerator::get_device` — that one hands `GetDevice` a freed string (see the helper's
+/// docs), and a spurious miss here silently downgrades a capturable default to `Unknown`.
+fn judge_default(wiring: &wiring_plan::Wiring, id: &str) -> DefaultKind {
+    let Ok(dev) = super::pad_endpoint::open_wasapi_device(id) else {
         return DefaultKind::Unknown;
     };
     let name = dev.get_friendlyname().unwrap_or_default();
@@ -736,7 +739,15 @@ fn judge_default(en: &DeviceEnumerator, wiring: &wiring_plan::Wiring, id: &str)
         .mic_render
         .as_ref()
         .is_some_and(|(_, mic_id)| mic_id == id);
-    if is_mic || wiring_plan::excluded_from_loopback(&ln) {
+    // B10: a pad's audio endpoint is not ordinary hardware, and the name rules cannot see that —
+    // it is deliberately stamped with the controller's own name ("DualSense Wireless Controller")
+    // so games treat it as the pad's speaker, which means `excluded_from_loopback` passes it
+    // straight through as `Capturable`. The pure plan filtered these out, but the plan is not the
+    // only reader: this classifier drives the watchdog, Follow mode and the parked default, so a
+    // pad endpoint that happened to be the system default could be adopted as the desktop capture
+    // source — sending the whole desktop mix to a controller's voice coils. Identity, not name.
+    let is_pad = super::pad_endpoint::is_pad_render_endpoint(id);
+    if is_mic || is_pad || wiring_plan::excluded_from_loopback(&ln) {
         DefaultKind::Dud(name)
     } else {
         DefaultKind::Capturable(name)

crates/punktfunk-host/src/audio/windows/wasapi_mic.rs

@@ -253,25 +253,16 @@ pub(crate) fn install_steam_audio_pair() -> bool {
     mic || spk
 }
 
-/// Install one Steam Streaming driver INF by filename via `DiInstallDriverW` (loaded from
-/// `newdev.dll`, like Apollo, to avoid an extra windows-crate feature). See
-/// [`install_steam_audio_pair`] for the contract; `inf_name` is a bare filename under Steam's
-/// per-arch `drivers\Windows10\{arch}\` directory.
-///
-/// Safe: `inf_name` is a `&str` and every FFI argument is built locally from it, so there is no
-/// precondition a caller could break — the `unsafe` is the `LoadLibraryExW`/`transmute`/call chain
-/// inside, which is this function's own business.
-fn try_install_steam_audio(inf_name: &str) -> bool {
-    use windows::core::{s, w, PCWSTR};
-    use windows::Win32::Foundation::HWND;
+/// Full path of a Steam Remote Play driver INF under Steam's per-arch driver directory
+/// (`%CommonProgramFiles(x86)%\Steam\drivers\Windows10\{arch}\<inf_name>`), as a NUL-terminated
+/// UTF-16 buffer. Shared by [`try_install_steam_audio`] and the pad-endpoint provisioning
+/// ([`super::pad_endpoint`]), which feeds the same INF to `UpdateDriverForPlugAndPlayDevicesW`
+/// when no installed Steam Streaming Speakers devnode exposes its `oemNN.inf`. `None` when the
+/// environment expansion fails (existence is the caller's check).
+pub(crate) fn steam_driver_inf_path(inf_name: &str) -> Option<Vec<u16>> {
+    use windows::core::PCWSTR;
     use windows::Win32::System::Environment::ExpandEnvironmentStringsW;
-    use windows::Win32::System::LibraryLoader::{
-        GetProcAddress, LoadLibraryExW, LOAD_LIBRARY_SEARCH_SYSTEM32,
-    };
 
-    if std::env::var_os("PUNKTFUNK_NO_MIC_INSTALL").is_some() {
-        return false;
-    }
     // Steam ships per-arch driver INFs under `Steam\drivers\Windows10\{arch}\`.
     #[cfg(target_arch = "x86_64")]
     let subdir = "x64";
@@ -290,8 +281,33 @@ fn try_install_steam_audio(inf_name: &str) -> bool {
     let n =
         unsafe { ExpandEnvironmentStringsW(PCWSTR(template.as_ptr()), Some(path.as_mut_slice())) };
     if n == 0 || n as usize > path.len() {
+        return None;
+    }
+    path.truncate(n as usize); // keeps the NUL
+    Some(path)
+}
+
+/// Install one Steam Streaming driver INF by filename via `DiInstallDriverW` (loaded from
+/// `newdev.dll`, like Apollo, to avoid an extra windows-crate feature). See
+/// [`install_steam_audio_pair`] for the contract; `inf_name` is a bare filename under Steam's
+/// per-arch `drivers\Windows10\{arch}\` directory.
+///
+/// Safe: `inf_name` is a `&str` and every FFI argument is built locally from it, so there is no
+/// precondition a caller could break — the `unsafe` is the `LoadLibraryExW`/`transmute`/call chain
+/// inside, which is this function's own business.
+fn try_install_steam_audio(inf_name: &str) -> bool {
+    use windows::core::{s, w, PCWSTR};
+    use windows::Win32::Foundation::HWND;
+    use windows::Win32::System::LibraryLoader::{
+        GetProcAddress, LoadLibraryExW, LOAD_LIBRARY_SEARCH_SYSTEM32,
+    };
+
+    if std::env::var_os("PUNKTFUNK_NO_MIC_INSTALL").is_some() {
         return false;
     }
+    let Some(path) = steam_driver_inf_path(inf_name) else {
+        return false;
+    };
 
     // SAFETY: a static NUL-terminated literal, loaded from System32 only (the flag), so this cannot
     // pick up a planted `newdev.dll` from the working directory. The handle is checked before use.

crates/punktfunk-host/src/audio/wiring_plan.rs

@@ -186,6 +186,17 @@ fn virtualish(lname: &str) -> bool {
         || lname.contains("voicemeeter")
 }
 
+/// Is this render endpoint id one of the virtual pad's audio endpoints?
+///
+/// Pulled out of [`plan`] because the plan is NOT the only place that must not treat these as
+/// ordinary hardware — see [`excluded_from_loopback`]'s callers. A pad endpoint is deliberately
+/// stamped with the controller's own name ("DualSense Wireless Controller") so games read it as
+/// the pad's speaker, which means no name-based rule can recognise one; the only reliable test is
+/// identity against the ids the pad-endpoint provisioner created.
+pub(crate) fn is_pad_render(id: &str, pad_renders: &[String]) -> bool {
+    pad_renders.iter().any(|p| p == id)
+}
+
 /// Compute the assignment. `mic_want` is the operator override (`PUNKTFUNK_MIC_DEVICE`,
 /// lowercased): when set it beats the built-in candidate order for the mic target. `host_audio`
 /// flips the loopback preference to real hardware (audio audible on the host too); the default
@@ -195,8 +206,17 @@ pub(crate) fn plan(
     captures: &[Endpoint],
     mic_want: Option<&str>,
     host_audio: bool,
+    pad_renders: &[String],
 ) -> Wiring {
-    plan_with_formats(renders, captures, mic_want, host_audio, &no_formats, 2)
+    plan_with_formats(
+        renders,
+        captures,
+        mic_want,
+        host_audio,
+        &no_formats,
+        2,
+        pad_renders,
+    )
 }
 
 /// [`plan`] with knowledge of each render endpoint's engine mix format, and the channel count the
@@ -221,7 +241,20 @@ pub(crate) fn plan_with_formats(
     host_audio: bool,
     format_of: FormatProbe,
     want_channels: u8,
+    pad_renders: &[String],
 ) -> Wiring {
+    // 0. Pad-audio endpoints are invisible to the plan: never the mic target (client voice
+    //    would play out of a pad "speaker"), never a loopback source (a game's controller
+    //    audio cues would stream as desktop audio), and — since this shadows `renders` for
+    //    every tier below — never the flagged last resort either. Their names carry no virtual
+    //    marker (they are stamped "DualSense Wireless Controller" on purpose, so games read
+    //    them as the pad's speaker), so the name rules alone would take one for real hardware.
+    let renders: Vec<Endpoint> = renders
+        .iter()
+        .filter(|(_, id)| !is_pad_render(id, pad_renders))
+        .cloned()
+        .collect();
+    let renders = renders.as_slice();
     let find_render = |needle: &str| {
         renders
             .iter()
@@ -422,7 +455,7 @@ mod tests {
             ep("Microphone (Webcam)"),
             ep("CABLE Output (VB-Audio Virtual Cable)"),
         ];
-        let w = plan(&renders, &captures, None, false);
+        let w = plan(&renders, &captures, None, false, &[]);
         assert_eq!(
             w.mic_render.unwrap().0,
             "CABLE Input (VB-Audio Virtual Cable)"
@@ -451,7 +484,7 @@ mod tests {
             ep("CABLE Output (VB-Audio Virtual Cable)"),
             ep("Microphone (Steam Streaming Microphone)"),
         ];
-        let w = plan(&renders, &captures, None, false);
+        let w = plan(&renders, &captures, None, false, &[]);
         assert_eq!(
             w.mic_render.unwrap().0,
             "CABLE Input (VB-Audio Virtual Cable)"
@@ -471,7 +504,7 @@ mod tests {
             ep("CABLE Input (VB-Audio Virtual Cable)"),
             ep("Speakers (Steam Streaming Microphone)"),
         ];
-        let w = plan(&renders, &[], None, true);
+        let w = plan(&renders, &[], None, true, &[]);
         assert_eq!(
             w.loopback_render.unwrap().0,
             "Speakers (Apple Audio Device)"
@@ -488,7 +521,7 @@ mod tests {
             ep("CABLE In 16ch (VB-Audio Virtual Cable)"),
         ];
         for host_audio in [false, true] {
-            let w = plan(&renders, &[], None, host_audio);
+            let w = plan(&renders, &[], None, host_audio, &[]);
             assert!(w.loopback_render.is_none(), "host_audio={host_audio}");
         }
     }
@@ -500,7 +533,7 @@ mod tests {
     fn headless_cable_only_mic_wins() {
         let renders = [ep("CABLE Input (VB-Audio Virtual Cable)")];
         let captures = [ep("CABLE Output (VB-Audio Virtual Cable)")];
-        let w = plan(&renders, &captures, None, false);
+        let w = plan(&renders, &captures, None, false, &[]);
         assert!(w.mic_render.is_some(), "mic must claim the only cable");
         assert!(w.loopback_render.is_none(), "no echo-safe loopback exists");
     }
@@ -518,7 +551,7 @@ mod tests {
             ep("CABLE Output (VB-Audio Virtual Cable)"),
             ep("Microphone (Steam Streaming Microphone)"),
         ];
-        let w = plan(&renders, &captures, None, false);
+        let w = plan(&renders, &captures, None, false, &[]);
         assert_eq!(
             w.mic_render.unwrap().0,
             "CABLE Input (VB-Audio Virtual Cable)"
@@ -546,7 +579,7 @@ mod tests {
             ep("Speakers (Realtek HD Audio)"),
         ];
         let captures = [ep("Microphone (Steam Streaming Microphone)")];
-        let w = plan(&renders, &captures, None, false);
+        let w = plan(&renders, &captures, None, false, &[]);
         assert_eq!(
             w.mic_render.unwrap().0,
             "Speakers (Steam Streaming Microphone)"
@@ -560,7 +593,7 @@ mod tests {
     fn steam_mic_only_no_echo() {
         let renders = [ep("Speakers (Steam Streaming Microphone)")];
         let captures = [ep("Microphone (Steam Streaming Microphone)")];
-        let w = plan(&renders, &captures, None, false);
+        let w = plan(&renders, &captures, None, false, &[]);
         assert!(w.mic_render.is_some());
         assert!(w.loopback_render.is_none());
     }
@@ -576,7 +609,7 @@ mod tests {
             ep("Speakers (Steam Streaming Speakers)"),
         ];
         for host_audio in [false, true] {
-            let w = plan(&renders, &[], None, host_audio);
+            let w = plan(&renders, &[], None, host_audio, &[]);
             assert_eq!(
                 w.loopback_render.as_ref().unwrap().0,
                 "Speakers (Steam Streaming Speakers)",
@@ -597,7 +630,7 @@ mod tests {
             ep("Altavoces (Steam Streaming Microphone)"),
         ];
         let captures = [ep("Microphone (Steam Streaming Microphone)")];
-        let w = plan(&renders, &captures, None, false);
+        let w = plan(&renders, &captures, None, false, &[]);
         assert_eq!(
             w.mic_render.unwrap().0,
             "Altavoces (Steam Streaming Microphone)"
@@ -620,7 +653,7 @@ mod tests {
         ];
         let captures = [ep("Microphone (Steam Streaming Microphone)")];
         for host_audio in [false, true] {
-            let w = plan(&renders, &captures, None, host_audio);
+            let w = plan(&renders, &captures, None, host_audio, &[]);
             assert_eq!(
                 w.loopback_render.as_ref().unwrap().0,
                 "Speakers (Realtek HD Audio)",
@@ -642,7 +675,7 @@ mod tests {
         ];
         let captures = [ep("CABLE Output (VB-Audio Virtual Cable)")];
         for host_audio in [false, true] {
-            let w = plan(&renders, &captures, None, host_audio);
+            let w = plan(&renders, &captures, None, host_audio, &[]);
             assert!(w.loopback_render.is_none(), "host_audio={host_audio}");
             assert!(!w.loopback_last_resort, "host_audio={host_audio}");
             assert!(w.loopback_unsatisfiable(), "host_audio={host_audio}");
@@ -691,7 +724,7 @@ mod tests {
             ("steam streaming microphone", fmt(24_000, 1)),
             ("odyssey", fmt(48_000, 2)),
         ]);
-        let w = plan_with_formats(&renders, &captures, None, false, &p, 2);
+        let w = plan_with_formats(&renders, &captures, None, false, &p, 2, &[]);
         assert_eq!(
             w.loopback_render.as_ref().unwrap().0,
             "1 - Odyssey G60SD (AMD High Definition Audio Device)",
@@ -721,7 +754,7 @@ mod tests {
             ("steam streaming microphone", fmt(48_000, 2)),
             ("realtek", fmt(48_000, 2)),
         ]);
-        let w = plan_with_formats(&renders, &[], None, false, &p, 2);
+        let w = plan_with_formats(&renders, &[], None, false, &p, 2, &[]);
         assert_eq!(
             w.loopback_render.unwrap().0,
             "Speakers (Steam Streaming Microphone)"
@@ -737,7 +770,7 @@ mod tests {
             ep("Speakers (Steam Streaming Microphone)"),
         ];
         let p = probe(vec![("steam streaming microphone", fmt(16_000, 1))]);
-        let w = plan_with_formats(&renders, &[], None, false, &p, 2);
+        let w = plan_with_formats(&renders, &[], None, false, &p, 2, &[]);
         assert_eq!(
             w.loopback_render.as_ref().unwrap().0,
             "Speakers (Steam Streaming Microphone)"
@@ -753,7 +786,7 @@ mod tests {
     fn narrowing_is_reported_for_real_hardware_too() {
         let renders = [ep("Headset (Hands-Free AG Audio)")];
         let p = probe(vec![("headset", fmt(16_000, 1))]);
-        let w = plan_with_formats(&renders, &[], None, false, &p, 2);
+        let w = plan_with_formats(&renders, &[], None, false, &p, 2, &[]);
         assert_eq!(
             w.loopback_render.as_ref().unwrap().0,
             "Headset (Hands-Free AG Audio)"
@@ -773,8 +806,8 @@ mod tests {
         ];
         let captures = [ep("CABLE Output (VB-Audio Virtual Cable)")];
         for host_audio in [false, true] {
-            let a = plan(&renders, &captures, None, host_audio);
-            let b = plan_with_formats(&renders, &captures, None, host_audio, &no_formats, 2);
+            let a = plan(&renders, &captures, None, host_audio, &[]);
+            let b = plan_with_formats(&renders, &captures, None, host_audio, &no_formats, 2, &[]);
             assert_eq!(a, b, "host_audio={host_audio}");
             assert!(a.loopback_narrowing.is_none());
         }
@@ -792,7 +825,7 @@ mod tests {
             ("steam streaming microphone", fmt(24_000, 1)),
             ("realtek", fmt(48_000, 2)),
         ]);
-        let w = plan_with_formats(&renders, &[], None, true, &p, 2);
+        let w = plan_with_formats(&renders, &[], None, true, &p, 2, &[]);
         assert_eq!(w.loopback_render.unwrap().0, "Speakers (Realtek HD Audio)");
     }
 
@@ -820,7 +853,7 @@ mod tests {
             ep("Voicemeeter Input (VB-Audio Voicemeeter VAIO)"),
         ];
         let captures = [ep("Voicemeeter Out B1 (VB-Audio Voicemeeter VAIO)")];
-        let w = plan(&renders, &captures, Some("voicemeeter input"), false);
+        let w = plan(&renders, &captures, Some("voicemeeter input"), false, &[]);
         assert_eq!(
             w.mic_render.unwrap().0,
             "Voicemeeter Input (VB-Audio Voicemeeter VAIO)"
@@ -836,7 +869,7 @@ mod tests {
     #[test]
     fn no_virtual_device() {
         let renders = [ep("Speakers (Realtek HD Audio)")];
-        let w = plan(&renders, &[], None, false);
+        let w = plan(&renders, &[], None, false, &[]);
         assert!(w.mic_render.is_none());
         assert_eq!(w.loopback_render.unwrap().0, "Speakers (Realtek HD Audio)");
     }
@@ -854,7 +887,7 @@ mod tests {
         ];
         let captures = [ep("Voicemeeter Out B1 (VB-Audio Voicemeeter VAIO)")];
         for host_audio in [false, true] {
-            let w = plan(&renders, &captures, None, host_audio);
+            let w = plan(&renders, &captures, None, host_audio, &[]);
             assert_eq!(
                 w.mic_render.as_ref().unwrap().0,
                 "Voicemeeter Input (VB-Audio Voicemeeter VAIO)",
@@ -877,7 +910,7 @@ mod tests {
             ep("Voicemeeter Aux Input (VB-Audio Voicemeeter AUX VAIO)"),
         ];
         for host_audio in [false, true] {
-            let w = plan(&renders, &[], None, host_audio);
+            let w = plan(&renders, &[], None, host_audio, &[]);
             assert!(w.mic_render.is_some(), "host_audio={host_audio}");
             assert!(w.loopback_render.is_none(), "host_audio={host_audio}");
         }
@@ -892,7 +925,7 @@ mod tests {
             ep("CABLE Input (VB-Audio Virtual Cable)"),
             ep("Speakers (Some Virtual Audio Device)"),
         ];
-        let w = plan(&renders, &[], None, false);
+        let w = plan(&renders, &[], None, false, &[]);
         assert!(w.loopback_render.is_none());
     }
 
@@ -918,7 +951,7 @@ mod tests {
         // Field shape minus the Speakers (mic holds the Streaming Microphone, nothing else).
         let renders = [ep("Altavoces (Steam Streaming Microphone)")];
         let captures = [ep("Microphone (Steam Streaming Microphone)")];
-        let w = plan(&renders, &captures, None, false);
+        let w = plan(&renders, &captures, None, false, &[]);
         assert!(w.loopback_unsatisfiable());
         let msg = describe_no_loopback(&renders, &w);
         assert!(msg.contains("reserved for the virtual mic"), "{msg}");
@@ -929,10 +962,70 @@ mod tests {
         // anyway), while the Steam pair is the remedy that adds a capturable sink.
         let renders = [ep("CABLE Input (VB-Audio Virtual Cable)")];
         let captures = [ep("CABLE Output (VB-Audio Virtual Cable)")];
-        let w = plan(&renders, &captures, None, false);
+        let w = plan(&renders, &captures, None, false, &[]);
         assert!(w.loopback_unsatisfiable());
         let msg = describe_no_loopback(&renders, &w);
         assert!(msg.contains("install Steam"), "{msg}");
         assert!(!msg.contains("install VB-Audio Virtual Cable"), "{msg}");
     }
+
+    /// A stamped pad endpoint is invisible to the plan. Its name carries NO virtual marker — on
+    /// purpose, games must read it as the pad's speaker — so the name rules alone would classify
+    /// it as real hardware and hand it the loopback; only the id exclusion prevents that.
+    /// Measured fact: the wiring plan on the target box already enumerated a stamped endpoint.
+    #[test]
+    fn pad_endpoints_invisible() {
+        let renders = [
+            ep("DualSense Wireless Controller"),
+            ep("Speakers (Realtek HD Audio)"),
+        ];
+        let pads = [renders[0].1.clone()];
+        let w = plan(&renders, &[], None, false, &pads);
+        assert_eq!(w.loopback_render.unwrap().0, "Speakers (Realtek HD Audio)");
+        // Even an operator mic override matching the pad's name must not claim it; with the
+        // pad as the only render endpoint there is honestly no mic target and no loopback.
+        let w = plan(
+            &renders[..1],
+            &[],
+            Some("wireless controller"),
+            false,
+            &pads,
+        );
+        assert!(w.mic_render.is_none());
+        assert!(w.loopback_render.is_none());
+    }
+
+    /// The exclusion has to survive the LAST RESORT tier, which this merge introduced alongside
+    /// pad audio. `last_resort` matches on the Steam-Speakers name, but it reads the same
+    /// shadowed `renders`, so a pad can never be reached through it either — otherwise the whole
+    /// desktop mix would be routed into the controller's voice coils.
+    #[test]
+    fn a_pad_is_never_the_last_resort() {
+        // Only the pad and the Steam pair exist; the mic reserves the Streaming Microphone, so
+        // the plan falls all the way through to the last resort.
+        let renders = [
+            ep("DualSense Wireless Controller"),
+            ep("Speakers (Steam Streaming Microphone)"),
+            ep("Speakers (Steam Streaming Speakers)"),
+        ];
+        let captures = [ep("Microphone (Steam Streaming Microphone)")];
+        let pads = [renders[0].1.clone()];
+        let w = plan(&renders, &captures, None, false, &pads);
+        assert_eq!(
+            w.loopback_render.as_ref().unwrap().0,
+            "Speakers (Steam Streaming Speakers)",
+            "the last resort must skip the pad"
+        );
+        assert!(w.loopback_last_resort);
+
+        // …and with the pad as the ONLY candidate left, the plan stays honestly unsatisfiable
+        // rather than falling back onto the coils.
+        let w = plan(&renders[..1], &captures, None, false, &pads);
+        assert!(
+            w.loopback_render.is_none(),
+            "a pad was taken as the last resort"
+        );
+        assert!(!w.loopback_last_resort);
+        assert!(w.loopback_unsatisfiable());
+    }
 }

crates/punktfunk-host/src/detect.rs

@@ -16,6 +16,19 @@
 //! [`KNOWN`] as new forks appear) matched against running processes, registered OS services/units,
 //! and on-disk install markers. The platform back-ends (`detect/windows.rs`, `detect/linux.rs`)
 //! provide the raw facts; the matching + rendering here is portable and unit-tested.
+//!
+//! **Not every fingerprint is a conflict.** Only a host that is running, or that will start on its
+//! own, can take the ports or load a second virtual-display driver. A leftover `Program Files`
+//! folder from an uninstall, a binary on `PATH`, or a service registered but *disabled* clashes
+//! with nothing — Sunshine's and Apollo's uninstallers both leave their config/log directories
+//! behind, so treating mere presence as a conflict cries wolf on a machine whose other host is long
+//! gone. [`Evidence::is_active`] draws that line and [`Detection::is_active`] lifts it to the
+//! product; the warning surfaces (startup log, `/local/summary` → the web console's conflicts card,
+//! the `detect-conflicts` exit code) report **only** active detections, while the full report still
+//! lists the dormant ones as context for support. This matches the installer's own probe
+//! (`punktfunk-host.iss`'s `StreamHostEnabled`: service start type <= 2), which was narrowed to
+//! exactly this rule after a dormant Sunshine aborted a `winget install` in the field, and the tray,
+//! which dropped its always-on warning over a merely-installed Sunshine in `3e782852`.
 
 use std::sync::OnceLock;
 
@@ -73,17 +86,38 @@ impl Product {
 pub enum Evidence {
     /// A matching process is running **right now** (process/executable basename).
     Running { process: String },
-    /// An OS service / systemd unit for the product is registered (installed; may be stopped).
-    Service { name: String },
+    /// An OS service / systemd unit for the product is registered. `autostart` is the load-bearing
+    /// bit: a service that comes up on its own (Windows start type boot/system/automatic; an enabled
+    /// systemd unit) *will* clash, whereas a disabled/manual one is inert until someone starts it by
+    /// hand — at which point the `Running` evidence catches it on the next scan.
+    Service { name: String, autostart: bool },
     /// Installed on disk — a Program Files directory, a flatpak app id, or a binary on `PATH`.
+    /// Always dormant: files that nothing launches bind no ports.
     Installed { at: String },
 }
 
 impl Evidence {
+    /// Does this observation mean a conflicting host will actually take the ports / load a second
+    /// virtual-display driver? See the module docs — this is the whole false-alarm fix.
+    pub fn is_active(&self) -> bool {
+        match self {
+            Evidence::Running { .. } => true,
+            Evidence::Service { autostart, .. } => *autostart,
+            Evidence::Installed { .. } => false,
+        }
+    }
+
     fn render(&self) -> String {
         match self {
             Evidence::Running { process } => format!("running now ({process})"),
-            Evidence::Service { name } => format!("service {name}"),
+            Evidence::Service {
+                name,
+                autostart: true,
+            } => format!("service {name} (starts automatically)"),
+            Evidence::Service {
+                name,
+                autostart: false,
+            } => format!("service {name} (disabled/manual — dormant)"),
             Evidence::Installed { at } => format!("installed at {at}"),
         }
     }
@@ -105,12 +139,24 @@ impl Detection {
             .any(|e| matches!(e, Evidence::Running { .. }))
     }
 
-    /// A compact one-line label for the tray/console summary, e.g. `Sunshine (running)`.
+    /// True when this host is running **or** will start on its own — i.e. the detection is worth
+    /// warning a user about. A product seen only as files on disk or a disabled service is dormant
+    /// and reports `false`; see the module docs.
+    pub fn is_active(&self) -> bool {
+        self.evidence.iter().any(Evidence::is_active)
+    }
+
+    /// A compact one-line label for the console summary, e.g. `Sunshine (running)`. The qualifier
+    /// names what was actually observed, so a card built from these labels can never claim a
+    /// dormant install is running.
     pub fn label(&self) -> String {
+        let name = self.product.label();
         if self.is_running() {
-            format!("{} (running)", self.product.label())
+            format!("{name} (running)")
+        } else if self.is_active() {
+            format!("{name} (starts automatically)")
         } else {
-            self.product.label().to_string()
+            format!("{name} (installed, not running)")
         }
     }
 }
@@ -225,28 +271,66 @@ pub fn snapshot() -> &'static [Detection] {
     SNAPSHOT.get().map(Vec::as_slice).unwrap_or(&[])
 }
 
-/// Compact labels for the tray / web-console summary (e.g. `["Sunshine (running)", "Apollo"]`).
-pub fn summary_labels(detections: &[Detection]) -> Vec<String> {
-    detections.iter().map(Detection::label).collect()
+/// True if any detection is active — the one gate the warning surfaces share (startup log, the
+/// `detect-conflicts` exit code, the console card).
+pub fn any_active(detections: &[Detection]) -> bool {
+    detections.iter().any(Detection::is_active)
 }
 
-/// A full human-readable report: the blurb + one bullet per detected host with its evidence.
-/// Empty string when nothing was detected (callers gate on `is_empty()`).
+/// Compact labels for the web-console summary (e.g. `["Sunshine (running)"]`).
+///
+/// **Active detections only.** A dormant leftover (an uninstalled Sunshine's `Program Files` folder,
+/// a disabled service) is deliberately absent: this feeds the console's conflicts card, which exists
+/// to explain why clients cannot reach a working-looking host, and files that nothing launches never
+/// cause that. The full [`render_report`] still lists them for support.
+pub fn summary_labels(detections: &[Detection]) -> Vec<String> {
+    detections
+        .iter()
+        .filter(|d| d.is_active())
+        .map(Detection::label)
+        .collect()
+}
+
+/// A full human-readable report, split by whether the finding can actually clash. Empty string when
+/// nothing was detected at all (callers gate on `is_empty()`).
+///
+/// The dormant section is why this stays verbose where [`summary_labels`] is quiet: when a user asks
+/// "why does Punktfunk think I have Apollo?", the answer is the exact leftover path, and the report
+/// says in the same breath that it needs no action.
 pub fn render_report(detections: &[Detection]) -> String {
     if detections.is_empty() {
         return String::new();
     }
-    let mut s = String::from("Detected another game-streaming host on this machine.\n");
-    s.push_str(UNSUPPORTED_BLURB);
-    s.push_str("\n\nDetected:\n");
-    for d in detections {
+    let bullet = |d: &Detection| {
         let ev = d
             .evidence
             .iter()
             .map(Evidence::render)
             .collect::<Vec<_>>()
             .join("; ");
-        s.push_str(&format!("  \u{2022} {} \u{2014} {ev}\n", d.product.label()));
+        format!("  \u{2022} {} \u{2014} {ev}\n", d.product.label())
+    };
+    let (active, dormant): (Vec<_>, Vec<_>) = detections.iter().partition(|d| d.is_active());
+    let mut s = String::new();
+    if !active.is_empty() {
+        s.push_str("Detected another game-streaming host on this machine.\n");
+        s.push_str(UNSUPPORTED_BLURB);
+        s.push_str("\n\nDetected:\n");
+        for d in &active {
+            s.push_str(&bullet(d));
+        }
+    }
+    if !dormant.is_empty() {
+        if !active.is_empty() {
+            s.push('\n');
+        }
+        s.push_str(
+            "Also present but DORMANT — not running and not set to start on its own, so it clashes \
+with nothing and needs no action (typically leftovers from an uninstall):\n",
+        );
+        for d in &dormant {
+            s.push_str(&bullet(d));
+        }
     }
     s
 }
@@ -275,15 +359,19 @@ mod tests {
                 },
                 Evidence::Service {
                     name: "SunshineService".into(),
+                    autostart: true,
                 },
             ],
         );
         assert!(d.is_running());
+        assert!(d.is_active());
         assert_eq!(d.label(), "Sunshine (running)");
     }
 
+    /// The field case this split exists for: Apollo uninstalled, its `Program Files` folder left
+    /// behind. Nothing launches it, so it is NOT a conflict and must never reach the console card.
     #[test]
-    fn installed_only_is_not_running() {
+    fn a_leftover_install_dir_is_dormant_and_never_surfaces() {
         let d = det(
             Product::Apollo,
             vec![Evidence::Installed {
@@ -291,42 +379,77 @@ mod tests {
             }],
         );
         assert!(!d.is_running());
-        assert_eq!(d.label(), "Apollo");
+        assert!(!d.is_active(), "files on disk cannot bind a port");
+        assert_eq!(d.label(), "Apollo (installed, not running)");
+        assert!(summary_labels(std::slice::from_ref(&d)).is_empty());
+        assert!(!any_active(&[d]));
+    }
+
+    /// A registered-but-DISABLED service is the other half of the same false alarm: `service_exists`
+    /// used to count it, which disagreed with the installer's `Start <= 2` probe.
+    #[test]
+    fn a_disabled_service_is_dormant_but_an_autostart_one_is_not() {
+        let disabled = det(
+            Product::Sunshine,
+            vec![Evidence::Service {
+                name: "SunshineService".into(),
+                autostart: false,
+            }],
+        );
+        assert!(!disabled.is_active());
+        assert!(summary_labels(&[disabled]).is_empty());
+
+        let auto = det(
+            Product::Sunshine,
+            vec![Evidence::Service {
+                name: "SunshineService".into(),
+                autostart: true,
+            }],
+        );
+        assert!(auto.is_active());
+        assert!(!auto.is_running(), "registered to start != started");
+        assert_eq!(auto.label(), "Sunshine (starts automatically)");
+        assert_eq!(
+            summary_labels(&[auto]),
+            vec!["Sunshine (starts automatically)".to_string()]
+        );
     }
 
     #[test]
-    fn report_lists_every_product_and_the_blurb() {
-        let report = render_report(&[
-            det(
-                Product::Sunshine,
-                vec![Evidence::Running {
-                    process: "sunshine".into(),
-                }],
-            ),
-            det(
-                Product::Apollo,
-                vec![Evidence::Installed {
-                    at: "/usr/bin/apollo".into(),
-                }],
-            ),
-        ]);
+    fn report_separates_active_from_dormant_and_keeps_the_blurb() {
+        let active = det(
+            Product::Sunshine,
+            vec![Evidence::Running {
+                process: "sunshine".into(),
+            }],
+        );
+        let dormant = det(
+            Product::Apollo,
+            vec![Evidence::Installed {
+                at: "/usr/bin/apollo".into(),
+            }],
+        );
+        let report = render_report(&[active.clone(), dormant.clone()]);
         assert!(report.contains("UNSUPPORTED"));
+        // The bullets name the PRODUCT and let the evidence speak — `Detection::label`'s qualifier
+        // would only restate what follows the dash ("Sunshine (running) — running now (sunshine)").
+        // The qualifier is for `summary_labels`, which has no evidence text beside it.
         assert!(report.contains("Sunshine \u{2014} running now (sunshine)"));
+        assert!(report.contains("DORMANT"));
         assert!(report.contains("Apollo \u{2014} installed at /usr/bin/apollo"));
+        // Only the live one is offered to the console card.
         assert_eq!(
-            summary_labels(&[
-                det(
-                    Product::Sunshine,
-                    vec![Evidence::Running {
-                        process: "sunshine".into()
-                    }]
-                ),
-                det(
-                    Product::Apollo,
-                    vec![Evidence::Installed { at: "x".into() }]
-                ),
-            ]),
-            vec!["Sunshine (running)".to_string(), "Apollo".to_string()]
+            summary_labels(&[active, dormant.clone()]),
+            vec!["Sunshine (running)".to_string()]
+        );
+
+        // A dormant-only machine gets the explanatory listing WITHOUT the "unsupported" alarm — the
+        // whole point is that this needs no action.
+        let dormant_only = render_report(&[dormant]);
+        assert!(dormant_only.contains("DORMANT"));
+        assert!(
+            !dormant_only.contains("UNSUPPORTED"),
+            "a leftover folder must not read as an unsupported dual-host setup:\n{dormant_only}"
         );
     }
 

crates/punktfunk-host/src/detect/linux.rs

@@ -50,7 +50,11 @@ pub fn static_evidence(known: &Known) -> Vec<Evidence> {
     for unit in known.linux_units {
         let file = format!("{unit}.service");
         if unit_dirs.iter().any(|d| Path::new(d).join(&file).exists()) {
-            ev.push(Evidence::Service { name: file });
+            let autostart = unit_enabled(&file, home.as_deref());
+            ev.push(Evidence::Service {
+                name: file,
+                autostart,
+            });
         }
     }
 
@@ -78,6 +82,49 @@ pub fn static_evidence(known: &Known) -> Vec<Evidence> {
     ev
 }
 
+/// Is `unit` (a `<name>.service` filename) **enabled** — i.e. will systemd start it on its own?
+///
+/// `systemctl enable` works by symlinking the unit into a target's `.wants`/`.requires` directory,
+/// so the presence of that link is the enablement fact — readable without spawning `systemctl`
+/// (this module is deliberately subprocess-free, and the host often runs where `systemctl` output
+/// would need a bus connection anyway). A unit file that exists but is linked from no target is
+/// installed-but-inert: nothing starts it at boot, so it clashes with nothing.
+///
+/// Scans the `.wants`/`.requires` subdirectories of the drop-in roots systemd actually reads, rather
+/// than hardcoding `multi-user.target` — a unit pulled in by `graphical.target`, a user
+/// `default.target`, or any other target is just as enabled.
+fn unit_enabled(unit: &str, home: Option<&std::ffi::OsStr>) -> bool {
+    let mut roots: Vec<String> = vec![
+        "/etc/systemd/system".into(),
+        "/run/systemd/system".into(),
+        "/usr/lib/systemd/system".into(),
+        "/lib/systemd/system".into(),
+        "/etc/systemd/user".into(),
+        "/usr/lib/systemd/user".into(),
+    ];
+    if let Some(h) = home {
+        roots.push(format!("{}/.config/systemd/user", h.to_string_lossy()));
+    }
+    for root in roots {
+        let Ok(entries) = std::fs::read_dir(&root) else {
+            continue;
+        };
+        for entry in entries.flatten() {
+            let name = entry.file_name();
+            let name = name.to_string_lossy();
+            if !(name.ends_with(".wants") || name.ends_with(".requires")) {
+                continue;
+            }
+            // `symlink_metadata` so a DANGLING link still counts: a link into a target's .wants is
+            // what "enabled" means, and a broken one still says the operator enabled it.
+            if std::fs::symlink_metadata(entry.path().join(unit)).is_ok() {
+                return true;
+            }
+        }
+    }
+    false
+}
+
 fn find_on_path(bin: &str, path: Option<&std::ffi::OsStr>) -> Option<String> {
     let dirs = path.map(std::env::split_paths).into_iter().flatten();
     // Always also probe the common bindirs, even if PATH is unset/narrow (e.g. a service context).

crates/punktfunk-host/src/detect/windows.rs

@@ -7,7 +7,7 @@ use windows::Win32::Foundation::CloseHandle;
 use windows::Win32::System::Diagnostics::ToolHelp::{
     CreateToolhelp32Snapshot, Process32FirstW, Process32NextW, PROCESSENTRY32W, TH32CS_SNAPPROCESS,
 };
-use windows_service::service::ServiceAccess;
+use windows_service::service::{ServiceAccess, ServiceStartType};
 use windows_service::service_manager::{ServiceManager, ServiceManagerAccess};
 
 /// Lowercased executable basenames (without `.exe`) of every running process, via a Toolhelp
@@ -49,9 +49,10 @@ pub fn running_processes() -> Vec<String> {
 pub fn static_evidence(known: &Known) -> Vec<Evidence> {
     let mut ev = Vec::new();
     for svc in known.win_services {
-        if service_exists(svc) {
+        if let Some(autostart) = service_start_type(svc) {
             ev.push(Evidence::Service {
                 name: (*svc).to_string(),
+                autostart,
             });
         }
     }
@@ -63,14 +64,35 @@ pub fn static_evidence(known: &Known) -> Vec<Evidence> {
     ev
 }
 
-/// True if a service by this name is registered with the SCM (running or stopped). Opening it with
-/// `QUERY_STATUS` fails cleanly when it doesn't exist.
-fn service_exists(name: &str) -> bool {
-    let Ok(mgr) = ServiceManager::local_computer(None::<&str>, ServiceManagerAccess::CONNECT)
-    else {
-        return false;
-    };
-    mgr.open_service(name, ServiceAccess::QUERY_STATUS).is_ok()
+/// `Some(autostart)` if a service by this name is registered with the SCM (running or stopped),
+/// `None` if it does not exist. Opening it fails cleanly when it doesn't exist.
+///
+/// `autostart` mirrors the installer's `StreamHostEnabled` (start type <= 2): only boot/system/auto
+/// come up on their own, and only a host that comes up can take the GameStream ports. A disabled or
+/// manual service is dormant — see the module docs on `super`. When the start type cannot be read
+/// (no `QUERY_CONFIG` right) we report the service as dormant rather than guessing it autostarts:
+/// the false-alarm this whole split exists to kill is worse than a missed warning, and a host that
+/// is genuinely up is caught by the process scan regardless of what its service config says.
+fn service_start_type(name: &str) -> Option<bool> {
+    let mgr = ServiceManager::local_computer(None::<&str>, ServiceManagerAccess::CONNECT).ok()?;
+    let svc = mgr
+        .open_service(
+            name,
+            ServiceAccess::QUERY_CONFIG | ServiceAccess::QUERY_STATUS,
+        )
+        // Fall back to a status-only handle so a service we may not configure still registers as
+        // present (dormant) instead of vanishing from the report entirely.
+        .or_else(|_| mgr.open_service(name, ServiceAccess::QUERY_STATUS))
+        .ok()?;
+    let autostart = svc.query_config().is_ok_and(|c| {
+        matches!(
+            c.start_type,
+            ServiceStartType::AutoStart
+                | ServiceStartType::BootStart
+                | ServiceStartType::SystemStart
+        )
+    });
+    Some(autostart)
 }
 
 /// The install directory under any of the Program Files roots, if it exists.

crates/punktfunk-host/src/devtest.rs

@@ -384,6 +384,7 @@ pub fn dualsense_windows_test(args: &[String]) -> Result<()> {
                 index: idx,
                 kind: 2,
                 capabilities: 0,
+                audio_caps: 0,
             });
             println!(
                 "virtual {} up — cycling Cross + sweeping the left stick for {secs}s. Watch \
@@ -430,6 +431,7 @@ pub fn dualsense_windows_test(args: &[String]) -> Result<()> {
             index: idx,
             kind: 1,
             capabilities: 0,
+            audio_caps: 0,
         });
         println!(
             "virtual Xbox 360 (XUSB) up — sweeping LS + toggling A for {secs}s. Check with \
@@ -486,6 +488,119 @@ pub fn dualsense_windows_test(args: &[String]) -> Result<()> {
     Ok(())
 }
 
+/// Windows: pad-audio endpoint provisioning — `pad-endpoint ensure|remove|status [--index N]`.
+/// `ensure` runs the idempotent startup path (reuse-or-create the devnode, bind the Steam
+/// Streaming Speakers driver, stamp the DualSense identity + 4ch/48k formats, report whether
+/// the stamps are SERVED); `status` prints the devnode/endpoint and per-stamp stored vs served
+/// state without changing anything; `remove` deletes the devnode via pnputil — the escape
+/// hatch only, endpoints are persistent by design. Stamping needs SYSTEM (the MMDevices ACL);
+/// run `ensure` under the service account or PsExec when the property-store route is denied.
+#[cfg(target_os = "windows")]
+pub fn pad_endpoint(args: &[String]) -> Result<()> {
+    use crate::audio::pad_endpoint as pe;
+    let idx: u8 = args
+        .iter()
+        .skip_while(|a| *a != "--index")
+        .nth(1)
+        .and_then(|s| s.parse().ok())
+        .unwrap_or(0);
+    // `--endpoint <id>` drives ANY render endpoint, not just a provisioned pad one. It is the
+    // discriminator between "this process cannot activate anything" and "our endpoint is broken":
+    // aim the same binary at a known-good endpoint and see whether it succeeds there.
+    let endpoint_override: Option<String> = args
+        .iter()
+        .skip_while(|a| *a != "--endpoint")
+        .nth(1)
+        .cloned();
+    match args.get(1).map(String::as_str) {
+        Some("ensure") => {
+            let p = pe::ensure(idx)?;
+            println!(
+                "pad-endpoint ensure: pad {} devnode {} endpoint {} needs_aeb_kick={}",
+                p.pad_index, p.device_instance, p.endpoint_id, p.needs_aeb_kick
+            );
+            Ok(())
+        }
+        Some("remove") => match pe::find(idx)? {
+            Some(p) => {
+                pe::remove(&p);
+                println!(
+                    "pad-endpoint remove: requested removal of {}",
+                    p.device_instance
+                );
+                Ok(())
+            }
+            None => {
+                println!("pad-endpoint remove: no pad-audio devnode for index {idx}");
+                Ok(())
+            }
+        },
+        // `punktfunk-host pad-endpoint <n> tone [seconds] [hz]` — drive the endpoint directly so
+        // the whole pad-audio chain can be exercised without a game. Without this, every attempt
+        // costs a game launch and a failure does not say which link broke.
+        Some("tone") => {
+            let secs: u32 = args.get(2).and_then(|s| s.parse().ok()).unwrap_or(5);
+            let hz: f32 = args.get(3).and_then(|s| s.parse().ok()).unwrap_or(60.0);
+            let endpoint_id = match endpoint_override {
+                Some(id) => id,
+                None => {
+                    // `find` (a system lookup), NOT `endpoint_for` (the service's in-process
+                    // cache): this runs as a separate CLI process and has no cache of its own.
+                    let Some(ep) = pe::find(idx)? else {
+                        println!(
+                            "pad-endpoint tone: no pad-audio devnode for pad {idx} — run \
+                             `ensure` first"
+                        );
+                        return Ok(());
+                    };
+                    if ep.endpoint_id.is_empty() {
+                        println!("pad-endpoint tone: pad {idx} has no endpoint id yet");
+                        return Ok(());
+                    }
+                    ep.endpoint_id
+                }
+            };
+            // `--pair front` drives the pad's SPEAKER instead of the voice coils — the only way to
+            // exercise the speaker kind without a game that renders one.
+            let pair = args
+                .iter()
+                .skip_while(|a| *a != "--pair")
+                .nth(1)
+                .map_or(pe::TonePair::Back, |s| pe::TonePair::parse(s));
+            println!(
+                "pad-endpoint tone: {hz} Hz into the {} of {endpoint_id} for {secs}s",
+                pair.label()
+            );
+            pe::render_test_tone(&endpoint_id, secs, hz, pair)?;
+            println!(
+                "pad-endpoint tone: done. A connected client with pad audio enabled should have \
+                 buzzed; the host log shows whether the gate opened."
+            );
+            Ok(())
+        }
+        // `punktfunk-host pad-endpoint capture [seconds]` — the receiving half of `tone`. Run
+        // both at once to exercise render -> engine -> loopback -> pair routing with no game and
+        // no client attached.
+        Some("capture") => {
+            let secs: u32 = args.get(2).and_then(|s| s.parse().ok()).unwrap_or(5);
+            let endpoint_id = match endpoint_override {
+                Some(id) => id,
+                None => match pe::find(idx)? {
+                    Some(ep) if !ep.endpoint_id.is_empty() => ep.endpoint_id,
+                    _ => {
+                        println!("pad-endpoint capture: pad {idx} has no endpoint — run `ensure`");
+                        return Ok(());
+                    }
+                },
+            };
+            println!("pad-endpoint capture: listening on {endpoint_id} for {secs}s");
+            pe::capture_probe(&endpoint_id, secs)
+        }
+        Some("status") => pe::print_status(idx),
+        _ => anyhow::bail!("usage: punktfunk-host pad-endpoint <ensure|remove|status> [--index N]"),
+    }
+}
+
 /// Mirror a physical monitor and pull frames from it — the on-glass gate for per-monitor capture
 /// (`design/per-monitor-portal-capture.md` P2/P3), without needing a client to connect.
 ///

crates/punktfunk-host/src/gamestream/cert.rs

@@ -26,6 +26,14 @@ impl ServerIdentity {
         let dir = config_dir();
         let cert_path = dir.join("cert.pem");
         let key_path = dir.join("key.pem");
+        // Harden the directory BEFORE the first read, not only in the branch that generates a new
+        // identity (2026-08-05 review M-1). Reading first is what made the hardening pointless
+        // against the attack it was written for: combined with H-4's pre-creatable
+        // `%ProgramData%\punktfunk`, a local user could plant a cert/key pair and have it adopted
+        // verbatim as the host's long-lived identity — the QUIC server key, the mgmt-API TLS key and
+        // the RSA pairing signer all becoming a key the attacker holds. The compromise is permanent:
+        // this function never regenerates while both files are non-empty.
+        pf_paths::create_private_dir(&dir).ok();
         let (cert_pem, key_pem) = match (
             fs::read_to_string(&cert_path),
             fs::read_to_string(&key_path),
@@ -35,8 +43,8 @@ impl ServerIdentity {
                 let (c, k) = generate()?;
                 // The private key is the trust root for EVERY surface (TLS server cert, pairing
                 // signing, the QUIC identity clients pin) — write it owner-only (0600 / SYSTEM-only
-                // DACL) so a local user can't read it and impersonate the host. The dir is 0700.
-                pf_paths::create_private_dir(&dir).ok();
+                // DACL) so a local user can't read it and impersonate the host. The dir is already
+                // 0700 / SYSTEM+Admins from the unconditional hardening above.
                 pf_paths::write_secret_file(&key_path, k.as_bytes())
                     .with_context(|| format!("write {}", key_path.display()))?;
                 // The cert is public (handed to clients), but write it owner-only too for consistency.