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-client-core/src/audio_wasapi.rs

@@ -60,7 +60,7 @@ impl AudioPlayer {
             .spawn(move || {
                 if let Err(e) = render_thread(pcm_rx, recycle_tx, stop_t, ready_tx, channels as u8)
                 {
-                    tracing::warn!(error = format!("{e:#}"), "audio playback thread ended");
+                    tracing::warn!(error = %format!("{e:#}"), "audio playback thread ended");
                 }
             })
             .context("spawn audio thread")?;
@@ -232,7 +232,7 @@ impl MicStreamer {
             .name("punktfunk-mic".into())
             .spawn(move || {
                 if let Err(e) = mic_thread(&connector, stop_t) {
-                    tracing::warn!(error = format!("{e:#}"), "mic uplink thread ended");
+                    tracing::warn!(error = %format!("{e:#}"), "mic uplink thread ended");
                 }
             })
             .context("spawn mic thread")?;

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

@@ -1493,7 +1493,7 @@ impl Worker {
             Err(e) => {
                 tracing::warn!(pad = slot.index, low, high, error = %e, "rumble: SDL set_rumble failed")
             }
-            Ok(()) => tracing::debug!(pad = slot.index, low, high, "rumble: rendered"),
+            Ok(()) => tracing::trace!(pad = slot.index, low, high, "rumble: rendered"),
         }
         slot.rumble.last = (low, high);
         slot.rumble.last_at = Some(Instant::now());

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

@@ -222,7 +222,7 @@ fn pump(
             preferred = punktfunk_core::quic::CODEC_PYROWAVE;
         } else {
             tracing::warn!(
-                "PUNKTFUNK_PREFER_PYROWAVE=1 but the presenter device failed the pyrowave                  probe — keeping the normal codec preference"
+                "PUNKTFUNK_PREFER_PYROWAVE=1 but the presenter device failed the pyrowave probe — keeping the normal codec preference"
             );
         }
     }
@@ -791,7 +791,7 @@ fn spawn_audio(
                                 buf.extend_from_slice(&pcm[..n]);
                                 player.push(buf);
                             }
-                            Err(e) => tracing::debug!(error = %e, "opus decode"),
+                            Err(e) => tracing::debug!(error = %e, "opus decode failed"),
                         }
                     }
                     Err(PunktfunkError::NoFrame) => {}

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

@@ -510,7 +510,7 @@ impl Decoder {
                     if choice == "vaapi" {
                         return Err(e.context("PUNKTFUNK_DECODER=vaapi but VAAPI failed"));
                     }
-                    tracing::info!(reason = %e, "VAAPI unavailable — software decode");
+                    tracing::warn!(error = %e, "VAAPI unavailable — falling back to software decode");
                 }
             }
         }
@@ -695,8 +695,8 @@ impl Decoder {
                     self.backend = Backend::Software(SoftwareDecoder::new(self.codec_id)?);
                     self.vaapi_fails = 0;
                 } else {
-                    tracing::warn!(error = %e,
-                        "{which} decode error — requesting keyframe, keeping hardware decode");
+                    tracing::debug!(backend = which, error = %e,
+                        "decode error — requesting keyframe, keeping hardware decode");
                 }
                 Ok(None)
             }
@@ -1653,7 +1653,7 @@ unsafe extern "C" fn pick_vulkan(
             &mut fr,
         );
         if r < 0 || fr.is_null() {
-            tracing::warn!("avcodec_get_hw_frames_parameters(VULKAN) failed ({r})");
+            tracing::warn!(code = r, "avcodec_get_hw_frames_parameters(VULKAN) failed");
             return ffi::AVPixelFormat::AV_PIX_FMT_NONE;
         }
         let fc = (*fr).data as *mut ffi::AVHWFramesContext;
@@ -1665,7 +1665,7 @@ unsafe extern "C" fn pick_vulkan(
             as _;
         let r = ffi::av_hwframe_ctx_init(fr);
         if r < 0 {
-            tracing::warn!("av_hwframe_ctx_init(VULKAN) failed ({r})");
+            tracing::warn!(code = r, "av_hwframe_ctx_init(VULKAN) failed");
             let mut fr = fr;
             ffi::av_buffer_unref(&mut fr);
             return ffi::AVPixelFormat::AV_PIX_FMT_NONE;

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

@@ -537,7 +537,8 @@ impl PyroWaveDecoder {
         let fence = device.create_fence(&vk::FenceCreateInfo::default(), None)?;
 
         tracing::info!(
-            mode = %format!("{width}x{height}"),
+            width,
+            height,
             "PyroWave decoder open on the presenter's device (compute iDWT, BT.709 limited)"
         );
         Ok(PyroWaveDecoder {
@@ -602,8 +603,8 @@ impl PyroWaveDecoder {
         });
         self.next = 0;
         tracing::info!(
-            from = %format!("{}x{}", self.width, self.height),
-            to = %format!("{width}x{height}"),
+            from = %format_args!("{}x{}", self.width, self.height),
+            to = %format_args!("{width}x{height}"),
             "PyroWave decoder rebuilt for mid-stream resize"
         );
         self.width = width;