feat(windows): pf-vdisplay IDD-push — HDR + pipelined zero-copy capture

HDR (display-driven, matching the WGC path):
- CTA-861.3 HDR EDID (BT.2020 primaries + HDR Static Metadata block) so Windows
  offers "Use HDR" on the virtual display. The host FOLLOWS the display's live
  advanced-color state, recreating the shared ring at the matching format
  (FP16 in HDR / BGRA in SDR) on a toggle — no freeze.
- Always emit Main10/BT.2020-PQ Rgb10a2 while the display is HDR; the client
  auto-detects PQ from the HEVC VUI (clients under-report VIDEO_CAP_10BIT).
  Generic HDR10 mastering SEI on every IDR.
- Generation-tagged `latest` (gen<<40|seq<<8|slot) + driver `is_stale` re-attach
  kill the toggle-time garbage frame and any stale-ring read.

Perf:
- Pipeline the encode loop (Capturer::pipeline_depth; IDD-push = 2): submit N+1
  before polling N so the convert/copy on the 3D engine overlaps the NVENC encode
  of N on the ASIC. PUNKTFUNK_IDD_DEPTH overrides (1 = synchronous).
- Rotating host output ring (OUT_RING) so the in-flight encode and the next
  convert never touch the same texture.
- HDR converts directly from the keyed-mutex slot's SRV into the output ring
  (drops the redundant slot->fp16 scratch copy); SDR copies the BGRA slot in.
  The slot mutex is held only across the convert/copy, not the encode.
  RING_LEN 3->6 for publish headroom.
- Capture-health diagnostic: new_fps vs repeat_fps under PUNKTFUNK_PERF (a low
  new_fps at a high send rate means the source isn't compositing, not an encode
  stall).

Validated live on the RTX box: 5120x1440@240 HDR streams; driver composes
~180 new fps, encode 240 fps @ ~4.3 ms p50.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

crates/punktfunk-core/src/quic.rs

@@ -1454,11 +1454,16 @@ pub mod endpoint {
     /// close, while a genuinely dead peer is still detected within `MAX_IDLE`.
     fn stream_transport() -> Arc<quinn::TransportConfig> {
         use std::time::Duration;
-        const MAX_IDLE: Duration = Duration::from_secs(20);
+        // 8s idle (was 20s): a vanished client is declared dead within 8s instead of 20, so its
+        // session tears down promptly — which the Windows IDD-push path needs so a RECONNECT recreates
+        // a fresh virtual monitor (a reused monitor's IddCx swap-chain dies) instead of joining the
+        // still-lingering old session. Active sessions are unaffected: video keeps the connection live,
+        // and the 4s keep-alive holds it open through quiet control periods.
+        const MAX_IDLE: Duration = Duration::from_secs(8);
         const KEEP_ALIVE: Duration = Duration::from_secs(4);
         let mut t = quinn::TransportConfig::default();
         t.max_idle_timeout(Some(
-            quinn::IdleTimeout::try_from(MAX_IDLE).expect("20s is a valid QUIC idle timeout"),
+            quinn::IdleTimeout::try_from(MAX_IDLE).expect("8s is a valid QUIC idle timeout"),
         ));
         t.keep_alive_interval(Some(KEEP_ALIVE));
         Arc::new(t)