feat(clients/windows): GPU picker, disconnect shortcut, richer stream HUD

- Settings gains a GPU selector (shown only on multi-GPU boxes): the picked
  DXGI adapter drives decode + present, persisted as Settings.adapter and
  applied at the next stream - gpu.rs now caches the shared device keyed by
  the resolved preference (env PUNKTFUNK_ADAPTER > Settings > the window's
  monitor's adapter) so a change needs no app restart.
- Ctrl+Alt+Shift+D disconnects the session (consumed locally, captured or
  released): the hook releases capture and trips the session stop flag,
  plumbed through the stream-page handoff; the pump winds down and the UI
  navigates back to the host list.
- Stream HUD extended: codec chip (HEVC/H.264/AV1), display-side line from
  the render thread (presents/s + capture-to-decoded vs capture-to-on-glass
  p50), session line (host name, duration, network-lost frames, skipped
  backlog frames), and both shortcut hints incl. the new disconnect.

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

clients/windows/src/trust.rs

@@ -144,6 +144,11 @@ pub struct Settings {
     /// preference — the host honors it when it can emit it, else falls back to the best shared codec.
     #[serde(default = "default_codec")]
     pub codec: String,
+    /// Decode/present GPU: the DXGI adapter description to prefer on a multi-GPU box; empty =
+    /// automatic (the adapter driving the window's monitor). Applies from the next session; a
+    /// vanished adapter (eGPU unplugged) falls back to automatic.
+    #[serde(default)]
+    pub adapter: String,
 }
 
 fn default_codec() -> String {
@@ -177,6 +182,7 @@ impl Default for Settings {
             hdr_enabled: true,
             decoder: "auto".into(),
             codec: "auto".into(),
+            adapter: String::new(),
         }
     }
 }