feat(client-linux): feature parity with the Swift client

Everything the macOS app does that stage 1 lacked, before any new
feature work (user directive):

- Input capture is now a deliberate, reversible STATE (Moonlight-
  style): engaged on stream start and click-into-video (the engaging
  click is suppressed), released by Ctrl+Alt+Shift+Q (toggles) or
  focus loss; held keys/buttons are flushed host-side on release;
  cursor hiding + shortcut inhibition follow the state; HUD hint when
  released. Per-session window handlers disconnect with the page.
- Gamepads: app-lifetime SDL service (GamepadManager parity) — pad
  list + "Forwarded controller" pin in Settings (auto = most recent),
  "Automatic" pad TYPE resolves from the physical pad at connect;
  DualSense touchpad contacts + ~250 Hz motion samples on the 0xCC
  plane (Swift GamepadWire scale constants); feedback grows adaptive-
  trigger replay and player LEDs via raw DS5 effects packets (the
  wire's 11-byte blocks drop into SDL_SendGamepadEffect verbatim);
  held pad state zeroed on pad switch/detach. sdl3 "hidapi" feature.
- Microphone uplink: PipeWire capture -> Opus 20 ms -> 0xCB datagrams
  (validated live: host received 711 mic packets), Settings toggle.
- Speed test per saved host (Swift's "Test Network Speed…"): 2 s
  probe burst, goodput/loss + recommended ~70 % bitrate, one-tap apply.
- Settings: host compositor preference (sent in the Hello), native-
  display resolution/refresh resolved from the window's monitor at
  connect (new default), bitrate ceiling to 3 Gbit/s.
- Hosts page: saved/trusted hosts section for direct pinned reconnect
  (mDNS not required), rebuilt on every page return.

Deliberately not ported: audio device pickers (PipeWire routing owns
this on Linux), resize-to-request_mode (not wired in Swift either),
pointer-lock relative mouse (stage-2 presenter, needs raw Wayland).
DualSense fidelity needs a physical pad to live-verify.

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

crates/punktfunk-client-linux/src/trust.rs

@@ -104,29 +104,39 @@ impl KnownHosts {
     }
 }
 
-/// App settings, persisted as JSON. Stringly-typed gamepad pref so the file stays
-/// readable; parsed with `GamepadPref::from_name` at connect time.
+/// App settings, persisted as JSON. Stringly-typed gamepad/compositor prefs so the file
+/// stays readable; parsed with `*Pref::from_name` at connect time.
 #[derive(Clone, Serialize, Deserialize)]
+#[serde(default)]
 pub struct Settings {
+    /// Stream mode; `0` = the native size/refresh of the monitor the window is on,
+    /// resolved at connect time.
     pub width: u32,
     pub height: u32,
     pub refresh_hz: u32,
     /// Requested encoder bitrate (kbps); 0 = host default.
     pub bitrate_kbps: u32,
     pub gamepad: String,
-    /// Grab compositor shortcuts (Alt+Tab, Super…) while streaming.
+    /// Which host compositor backend to request (advisory; the host falls back to
+    /// auto-detect when unavailable).
+    pub compositor: String,
+    /// Grab compositor shortcuts (Alt+Tab, Super…) while input is captured.
     pub inhibit_shortcuts: bool,
+    /// Stream the default microphone to the host's virtual mic source.
+    pub mic_enabled: bool,
 }
 
 impl Default for Settings {
     fn default() -> Self {
         Settings {
-            width: 1920,
-            height: 1080,
-            refresh_hz: 60,
+            width: 0,
+            height: 0,
+            refresh_hz: 0,
             bitrate_kbps: 0,
             gamepad: "auto".into(),
+            compositor: "auto".into(),
             inhibit_shortcuts: true,
+            mic_enabled: false,
         }
     }
 }