refactor: drop milestone names + consolidate clients; loss-recovery & rumble fixes

Two bodies of work in one commit (the rename moved files the fixes also touched).

Naming/structure cleanup (pre-launch):
- Host modules m3.rs->punktfunk1.rs, m0.rs->spike.rs; CLI m3-host->punktfunk1-host,
  m0->spike; bare `punktfunk-host` now prints help. Types M3Options/M3Source->
  Punktfunk1Options/Punktfunk1Source.
- Clients consolidated out of crates/ into clients/: punktfunk-client-rs->
  clients/probe (crate punktfunk-probe), client-linux->clients/linux,
  client-windows->clients/windows, punktfunk-android->clients/android/native
  (crate punktfunk-client-android; kept [lib] name=punktfunk_android so the JNI
  contract is unchanged). crates/ now holds only core + host.
- Milestone codes M0-M4 purged from code/CLI/CLAUDE.md/README/docs/docs-site,
  kept only in docs/implementation-plan.md. docs/m2-plan.md->
  docs/gamestream-host-plan.md. CI/gradle/flatpak paths updated.

Client loss-recovery (video froze and never recovered after a brief drop):
- Export punktfunk_connection_frames_dropped through the C ABI (the core already
  tracked it for the client keyframe-recovery loop; it was never reachable from
  the ABI clients). Regenerated punktfunk_core.h.
- Apple (StreamPump + Stage2Pipeline) and Android (decode.rs) now poll
  frames_dropped and request a keyframe when it climbs -- the same loss-driven
  recovery Linux/Windows already had. Under infinite GOP the decoder silently
  conceals reference-missing frames, so the decode-error trigger rarely fires.

Apple rumble robustness (worked then went spotty -- DualSense + Xbox):
- Add CHHapticEngine stopped/reset handlers (rebuild on app background / audio
  interruption / server reset) and drop the permanent `broken` latch on a
  transient drive failure; latch only when the controller truly has no haptics.
- Surface swallowed SDL set_rumble errors on Linux/Windows + diagnostic logging.

Verified: cargo build/clippy/fmt --workspace, C-ABI harness, header drift.
Not runnable on this box (verify in CI): Gitea workflows, gradle/Android,
flatpak, Swift/decky.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

clients/android/native/src/decode.rs

@@ -0,0 +1,160 @@
+//! Android video decode (android-only): pull HEVC access units from the connector and render them
+//! to the SurfaceView via NDK `AMediaCodec` — hardware decode, zero per-frame JNI.
+//!
+//! One-in/one-out: the host opens every stream with an IDR carrying VPS/SPS/PPS **in-band**, so the
+//! decoder needs no out-of-band codec-specific data — we configure with mime + the negotiated
+//! WxH (from [`NativeClient::mode`]) and feed each access unit as it arrives. The decode thread owns
+//! the codec + window for its whole life; [`crate::session`] signals it to stop via the shared flag.
+
+use ndk::media::media_codec::{
+    DequeuedInputBufferResult, DequeuedOutputBufferInfoResult, MediaCodec, MediaCodecDirection,
+};
+use ndk::media::media_format::MediaFormat;
+use ndk::native_window::NativeWindow;
+use punktfunk_core::client::NativeClient;
+use punktfunk_core::error::PunktfunkError;
+use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::Arc;
+use std::time::{Duration, Instant};
+
+/// The decode loop. Runs on the `pf-decode` thread until `shutdown` is set or the session closes.
+pub fn run(client: Arc<NativeClient>, window: NativeWindow, shutdown: Arc<AtomicBool>) {
+    let mode = client.mode();
+    let codec = match MediaCodec::from_decoder_type("video/hevc") {
+        Some(c) => c,
+        None => {
+            log::error!("decode: no HEVC decoder on this device");
+            return;
+        }
+    };
+
+    let mut format = MediaFormat::new();
+    format.set_str("mime", "video/hevc");
+    format.set_i32("width", mode.width as i32);
+    format.set_i32("height", mode.height as i32);
+    // Generous input buffer so a large keyframe AU is never truncated.
+    format.set_i32(
+        "max-input-size",
+        (mode.width * mode.height).max(2_000_000) as i32,
+    );
+    // Ask for the low-latency decode path where the decoder supports it (no reordering buffer).
+    format.set_i32("low-latency", 1);
+
+    if let Err(e) = codec.configure(&format, Some(&window), MediaCodecDirection::Decoder) {
+        log::error!("decode: configure failed: {e}");
+        return;
+    }
+    if let Err(e) = codec.start() {
+        log::error!("decode: start failed: {e}");
+        return;
+    }
+    log::info!(
+        "decode: HEVC decoder started at {}x{}",
+        mode.width,
+        mode.height
+    );
+
+    let mut fed: u64 = 0;
+    let mut rendered: u64 = 0;
+    // Loss recovery: watch the host→client unrecoverable-drop count and ask for an IDR when it
+    // climbs.
+    let mut last_dropped = client.frames_dropped();
+    let mut last_kf_req: Option<Instant> = None;
+    while !shutdown.load(Ordering::Relaxed) {
+        match client.next_frame(Duration::from_millis(5)) {
+            Ok(frame) => {
+                if fed == 0 {
+                    let p = &frame.data;
+                    log::info!(
+                        "decode: first AU {} bytes, head {:02x?}",
+                        p.len(),
+                        &p[..p.len().min(6)]
+                    );
+                }
+                fed += 1;
+                feed(&codec, &frame.data, frame.pts_ns / 1000);
+            }
+            Err(PunktfunkError::NoFrame) => {} // timeout — still drain output below
+            Err(_) => break,                   // session closed
+        }
+        rendered += drain(&codec);
+
+        // Loss recovery: under infinite GOP the only recovery keyframe is one we request. The
+        // reassembler drops unrecoverable AUs (frames_dropped); the decoder then conceals the
+        // reference-missing delta frames that follow and renders them without error, so keying off
+        // a decode error rarely fires. Request an IDR when the drop count climbs, throttled — the
+        // decode stays wedged for several frames until the IDR lands, so requesting every frame
+        // would flood the control stream.
+        let dropped = client.frames_dropped();
+        if dropped > last_dropped {
+            last_dropped = dropped;
+            let now = Instant::now();
+            if last_kf_req.is_none_or(|t| now.duration_since(t) >= Duration::from_millis(100)) {
+                last_kf_req = Some(now);
+                let _ = client.request_keyframe();
+                log::debug!("decode: requested keyframe (loss recovery, dropped={dropped})");
+            }
+        }
+
+        if fed > 0 && fed % 300 == 0 {
+            log::info!("decode: fed={fed} rendered={rendered}");
+        }
+    }
+
+    let _ = codec.stop();
+    log::info!("decode: stopped (fed={fed} rendered={rendered})");
+}
+
+/// Copy one access unit into a codec input buffer and queue it.
+fn feed(codec: &MediaCodec, au: &[u8], pts_us: u64) {
+    match codec.dequeue_input_buffer(Duration::from_millis(10)) {
+        Ok(DequeuedInputBufferResult::Buffer(mut buf)) => {
+            let n = {
+                let dst = buf.buffer_mut();
+                let n = au.len().min(dst.len());
+                if n < au.len() {
+                    log::warn!(
+                        "decode: AU {} > input buffer {}, truncated",
+                        au.len(),
+                        dst.len()
+                    );
+                }
+                for (slot, &b) in dst.iter_mut().zip(&au[..n]) {
+                    slot.write(b);
+                }
+                n
+            };
+            if let Err(e) = codec.queue_input_buffer(buf, 0, n, pts_us, 0) {
+                log::warn!("decode: queue_input_buffer: {e}");
+            }
+        }
+        Ok(DequeuedInputBufferResult::TryAgainLater) => {
+            // No input buffer free right now; the AU is dropped (FEC/keyframes recover).
+        }
+        Err(e) => log::warn!("decode: dequeue_input_buffer: {e}"),
+    }
+}
+
+/// Release any ready output buffers to the surface (render = true), latency-first. Returns the
+/// number of frames presented.
+fn drain(codec: &MediaCodec) -> u64 {
+    let mut n = 0;
+    loop {
+        match codec.dequeue_output_buffer(Duration::from_millis(0)) {
+            Ok(DequeuedOutputBufferInfoResult::Buffer(buf)) => {
+                if let Err(e) = codec.release_output_buffer(buf, true) {
+                    log::warn!("decode: release_output_buffer: {e}");
+                    break;
+                }
+                n += 1;
+            }
+            // TryAgainLater / OutputFormatChanged / OutputBuffersChanged — nothing to render now.
+            Ok(_) => break,
+            Err(e) => {
+                log::warn!("decode: dequeue_output_buffer: {e}");
+                break;
+            }
+        }
+    }
+    n
+}