chore: consolidate parallel-session WIP (HOLD — do not push)

Local snapshot of intermingled in-flight work, committed to unblock the encode
refactor (a clean ffmpeg_win.rs for the vbv-dedup follow-on). These hunks span
the same files and can't be cleanly split here; the commit bundles three
distinct workstreams that each belong in their own PR:

  - logging rework (~43 files: level re-tiering, structured fields, `?e`,
    hot-path flood latches)
  - conflicting-host detection (detect.rs + detect/{linux,windows}.rs + wiring
    in main.rs/mgmt.rs/Cargo.toml/docs/packaging)
  - standby-sink DWM-stall attribution (windows/display_events.rs + capture/
    vdisplay wiring)

NOT verified as a combination. NOT to be pushed until the refactor is done and
these are re-verified and reorganized into their proper per-workstream PRs.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

crates/punktfunk-host/src/vdisplay/linux/gamescope.rs

@@ -1278,7 +1278,7 @@ fn launch_session(client: &str, unit_name: &str, mode: Mode) -> Result<u32> {
         // and the transient unit has no Restart= — without supervision the rest of this poll would
         // wait on a corpse. Re-run the unit so every readiness attempt inside the deadline is used.
         if !unit_starting_or_active(unit_name) {
-            tracing::info!(
+            tracing::warn!(
                 unit = unit_name,
                 "gamescope session: transient unit died (missed the wrapper's 5 s gamescope \
                  readiness window?) — relaunching"

crates/punktfunk-host/src/vdisplay/linux/kwin.rs

@@ -685,7 +685,7 @@ fn run(
             .dispatch_pending(&mut state)
             .context("dispatch_pending")?;
         if state.closed {
-            tracing::warn!("KWin closed the virtual-output stream");
+            tracing::warn!(output = %name, node_id, "KWin closed the virtual-output stream");
             break;
         }
         conn.flush().context("wayland flush")?;

crates/punktfunk-host/src/vdisplay/linux/mutter.rs

@@ -255,12 +255,12 @@ fn session_thread(
             Ok(dc) => match get_state(&dc).await {
                 Ok(state) => Some((dc, state)),
                 Err(e) => {
-                    tracing::warn!("mutter: GetCurrentState (pre) failed ({e:#}); topology + scale persistence off");
+                    tracing::warn!(error = %format!("{e:#}"), "mutter: GetCurrentState (pre) failed; topology + scale persistence off");
                     None
                 }
             },
             Err(e) => {
-                tracing::warn!("mutter: DisplayConfig unavailable ({e:#}); topology + scale persistence off");
+                tracing::warn!(error = %format!("{e:#}"), "mutter: DisplayConfig unavailable; topology + scale persistence off");
                 None
             }
         };
@@ -301,14 +301,16 @@ fn session_thread(
                                 if exclusive { "disabled" } else { "kept" }
                             ),
                             Err(e) => tracing::warn!(
-                                "mutter: could not set the virtual output primary ({e:#}); streaming continues — the desktop may render on the physical monitor"
+                                error = %format!("{e:#}"),
+                                "mutter: could not set the virtual output primary; streaming continues — the desktop may render on the physical monitor"
                             ),
                         }
                     }
                     tracked = Some((dc, pre, vconn));
                 }
                 Err(e) => tracing::warn!(
-                    "mutter: virtual connector not identified ({e:#}); topology + scale persistence off"
+                    error = %format!("{e:#}"),
+                    "mutter: virtual connector not identified; topology + scale persistence off"
                 ),
             }
         }
@@ -737,7 +739,8 @@ async fn make_virtual_primary(
                 tracing::warn!(
                     scale,
                     derived,
-                    "mutter: ApplyMonitorsConfig at the remembered scale failed ({e:#}); retrying at the derived scale"
+                    error = %format!("{e:#}"),
+                    "mutter: ApplyMonitorsConfig at the remembered scale failed — retrying at the derived scale"
                 );
                 scale = derived;
             }

crates/punktfunk-host/src/vdisplay/policy.rs

@@ -234,9 +234,12 @@ pub struct DisplayPolicy {
     /// untouched.
     #[serde(default)]
     pub ddc_power_off: bool,
-    /// EXPERIMENTAL (Windows): after an `Exclusive` isolate deactivates the physical monitors,
-    /// additionally DISABLE their PnP device nodes (persistently, so a standby monitor/TV whose
-    /// hot-plug events re-arrive stays disabled) and re-enable them at restore. Targets the same
+    /// EXPERIMENTAL (Windows): DISABLE physical monitors' PnP device nodes for the stream's
+    /// duration (persistently, so a standby monitor/TV whose hot-plug events re-arrive stays
+    /// disabled) and re-enable them at teardown. Two selectors: the monitors an `Exclusive`
+    /// isolate deactivated, plus — in ANY topology — external monitors that are connected but not
+    /// part of the desktop (the standby TV that was never active, whose input auto-scan /
+    /// instant-on HPD cycling re-probes the link every few seconds). Targets the same
     /// "connected-but-dark head" periodic-stutter class as [`Self::ddc_power_off`], but at the
     /// Windows-reaction level: a disabled devnode's wake events trigger no PnP arrival, no CCD
     /// re-evaluation, no DWM invalidation. A crash-recovery journal re-enables leftovers on host

crates/punktfunk-host/src/vdisplay/windows/manager.rs

@@ -906,8 +906,9 @@ impl VirtualDisplayManager {
             Some(n) => {
                 tracing::info!(
                     backend = self.driver.name(),
-                    "target {} -> {n}",
-                    added.target_id
+                    target_id = added.target_id,
+                    gdi = %n,
+                    "IDD target activated into a display path"
                 );
                 // ADD only advertises the mode; force it active so DXGI captures the requested size.
                 set_active_mode(n, mode);
@@ -1015,6 +1016,26 @@ impl VirtualDisplayManager {
                     }
                 }
                 thread::sleep(Duration::from_millis(1500)); // let the topology settle before capture opens
+
+                // EXPERIMENTAL `pnp_disable_monitors`, second selector (ANY topology): monitors
+                // that are connected but NOT part of the desktop — the standby TV/monitor the
+                // deactivated-set selector above structurally misses (it never had an active path
+                // to deactivate), yet whose periodic standby wake events drive the same Windows
+                // reaction cascade (rationale in `windows/monitor_devnode.rs`). Runs AFTER the
+                // settle sleep so the active flags it reads are the committed ones (a display
+                // still mid-activation from the primary topology's force-EXTEND must not read as
+                // inactive and get disabled); in Extend the active physical panels are untouched
+                // by construction. First member only — the sweep is group-scoped like the
+                // isolate; later members join an already-swept desktop.
+                if first_member && crate::vdisplay::policy::prefs().pnp_disable_monitors() {
+                    let mut keep = inner.target_ids();
+                    keep.push(added.target_id);
+                    for id in crate::monitor_devnode::disable_connected_inactive(&keep) {
+                        if !inner.group.pnp_disabled.contains(&id) {
+                            inner.group.pnp_disabled.push(id);
+                        }
+                    }
+                }
             }
             None => tracing::warn!(
                 "virtual-display target {} not yet an active display path (auto-activate, EXTEND \
@@ -1067,8 +1088,11 @@ impl VirtualDisplayManager {
     ) -> Result<Monitor> {
         tracing::info!(
             slot,
-            old = %format!("{}x{}@{}", old.mode.width, old.mode.height, old.mode.refresh_hz),
-            new = %format!("{}x{}@{}", mode.width, mode.height, mode.refresh_hz),
+            old = format!(
+                "{}x{}@{}",
+                old.mode.width, old.mode.height, old.mode.refresh_hz
+            ),
+            new = format!("{}x{}@{}", mode.width, mode.height, mode.refresh_hz),
             old_target = old.target_id,
             "virtual-display: re-arriving monitor for a mid-stream resize (exact mode)"
         );
@@ -1207,17 +1231,19 @@ impl VirtualDisplayManager {
             // (stopped FIRST, as the per-monitor pinger was), and the group's topology restore runs
             // — first-in captured it, last-out restores it (design §6.1).
             self.stop_pinger();
+            // EXPERIMENTAL `pnp_disable_monitors` restore: re-enable the devnodes FIRST and let
+            // them re-arrive, so a CCD restore below re-activates paths whose monitors exist
+            // again (a disabled devnode would leave the restored path modeless/EDID-less).
+            // OUTSIDE the ccd_saved gate: the connected-inactive sweep disables devnodes in
+            // Extend/Primary sessions too, where no isolate snapshot exists to restore.
+            let pnp_disabled = std::mem::take(&mut inner.group.pnp_disabled);
+            if !pnp_disabled.is_empty() {
+                crate::monitor_devnode::enable_instances(&pnp_disabled);
+                thread::sleep(Duration::from_millis(300));
+            }
             // Re-attach detached display(s) BEFORE the REMOVE so the box is never left with zero
             // displays.
             if let Some(saved) = inner.group.ccd_saved.take() {
-                // EXPERIMENTAL `pnp_disable_monitors` restore: re-enable the devnodes FIRST and let
-                // them re-arrive, so the CCD restore below re-activates paths whose monitors exist
-                // again (a disabled devnode would leave the restored path modeless/EDID-less).
-                let pnp_disabled = std::mem::take(&mut inner.group.pnp_disabled);
-                if !pnp_disabled.is_empty() {
-                    crate::monitor_devnode::enable_instances(&pnp_disabled);
-                    thread::sleep(Duration::from_millis(300));
-                }
                 restore_displays_ccd(&saved);
                 // EXPERIMENTAL `ddc_power_off` wake: the restore re-activated the physical paths, and
                 // returning signal alone wakes DPMS-off panels on most firmware — the explicit ON is
@@ -1255,7 +1281,10 @@ impl VirtualDisplayManager {
             if is_device_gone(&e) {
                 self.invalidate_device(&e);
             }
-            tracing::warn!("virtual-display REMOVE failed: {e:#}");
+            tracing::warn!(
+                target_id = mon.target_id,
+                "virtual-display REMOVE failed: {e:#}"
+            );
         } else {
             tracing::info!(
                 backend = self.driver.name(),

crates/punktfunk-host/src/vdisplay/windows/pf_vdisplay.rs

@@ -164,10 +164,14 @@ fn restart_vdisplay_device() -> bool {
     {
         Ok(o) => {
             let status = String::from_utf8_lossy(&o.stdout).trim().to_string();
-            tracing::warn!(
-                %status,
-                "pf-vdisplay: cycled the adapter device (hostless-zombie recovery)"
-            );
+            if status == "ABSENT" {
+                tracing::warn!("pf-vdisplay: no adapter devnode to cycle — driver not installed");
+            } else {
+                tracing::warn!(
+                    %status,
+                    "pf-vdisplay: cycled the adapter device (hostless-zombie recovery)"
+                );
+            }
             status != "ABSENT"
         }
         Err(e) => {
@@ -531,13 +535,13 @@ impl VdisplayDriver for PfVdisplayDriver {
             HighPart: reply.adapter_luid_high,
         };
         tracing::info!(
-            "pf-vdisplay created {}x{}@{} (target_id={}, adapter_luid={:#x}, wudf_pid={})",
+            target_id = reply.target_id,
+            adapter_luid = %format_args!("{:#x}", luid.LowPart),
+            wudf_pid = reply.wudf_pid,
+            "pf-vdisplay monitor created {}x{}@{}",
             mode.width,
             mode.height,
-            mode.refresh_hz,
-            reply.target_id,
-            luid.LowPart,
-            reply.wudf_pid
+            mode.refresh_hz
         );
         // Per-client identity diagnostic: did the driver honor the host's preferred (stable) monitor id?
         // A pre-Phase-2 driver leaves resolved_monitor_id=0 (it ignored the field); a current driver echoes