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/pf-presenter/src/dmabuf.rs

@@ -101,7 +101,7 @@ pub fn import(
     // EGL could leave an INVALID modifier to the driver's implied choice; explicit-
     // modifier images can't — LINEAR is the only honest guess (debug-visible if wrong).
     let modifier = if frame.modifier == DRM_FORMAT_MOD_INVALID {
-        tracing::debug!("dmabuf carried no explicit modifier — importing as LINEAR");
+        tracing::trace!("dmabuf carried no explicit modifier — importing as LINEAR");
         DRM_FORMAT_MOD_LINEAR
     } else {
         frame.modifier

crates/pf-presenter/src/run.rs

@@ -184,6 +184,11 @@ struct StreamState {
     // Hardware-path health: a failure streak (or a device with no import support at
     // all) demotes the decoder to software via the shared flag — once per session.
     dmabuf_demoted: bool,
+    /// PyroWave present has no demote rung (nothing else decodes the codec), so a
+    /// persistent non-device-lost present failure would warn on every frame. Latch it:
+    /// warn on the first failure of a streak, then stay quiet until a present succeeds.
+    #[cfg(all(target_os = "linux", feature = "pyrowave"))]
+    pyro_present_warned: bool,
     hw_fails: u32,
     /// The OSD's text (multi-line; rebuilt each Stats window and on a live tier cycle).
     osd_text: String,
@@ -255,6 +260,8 @@ impl StreamState {
             win_start: Instant::now(),
             presented: PresentedWindow::default(),
             dmabuf_demoted: false,
+            #[cfg(all(target_os = "linux", feature = "pyrowave"))]
+            pyro_present_warned: false,
             hw_fails: 0,
             osd_text: String::new(),
             last_stats: None,
@@ -542,7 +549,7 @@ fn run_inner(mut opts: SessionOpts, mut mode: ModeCtl) -> Result<Option<Outcome>
                         fullscreen = !fullscreen;
                         tracing::debug!(fullscreen, "fullscreen toggle");
                         if let Err(e) = window.set_fullscreen(fullscreen) {
-                            tracing::warn!(error = %e, "fullscreen toggle");
+                            tracing::warn!(error = %e, fullscreen, "failed to toggle fullscreen");
                         }
                         continue;
                     }
@@ -985,13 +992,22 @@ fn run_inner(mut opts: SessionOpts, mut mode: ModeCtl) -> Result<Option<Outcome>
                             FrameInput::PyroWave(f),
                             overlay_frame.as_ref(),
                         ) {
-                            Ok(p) => p,
+                            Ok(p) => {
+                                st.pyro_present_warned = false;
+                                p
+                            }
                             Err(e) => {
                                 if device_lost(&e) {
                                     return Err(e)
                                         .context("GPU device lost — the session cannot continue");
                                 }
-                                tracing::warn!(error = %format!("{e:#}"), "pyrowave present failed");
+                                if !st.pyro_present_warned {
+                                    st.pyro_present_warned = true;
+                                    tracing::warn!(
+                                        error = %format!("{e:#}"),
+                                        "pyrowave present failed — suppressing repeats until it recovers"
+                                    );
+                                }
                                 false
                             }
                         }