fix(call): Wave-1 audit fixes (calls host side)

- C-H1: forceState only on FIRST join; on EC reconnect re-arm the fork handlers
  (resendForkState — deafen+quality only) instead of clobbering live mic/video/
  deafen back to the join-time snapshot.
- C-H2: AFK auto-mute reads the fork's io.lotus.call_state VAD of the LOCAL
  published track instead of getUserMedia on the browser DEFAULT mic (which could
  measure silence while the user spoke on another device → auto-mute an active
  speaker). Fails safe (never mutes) when call_state is null OR empty.
- C-H3: control observer re-binds after EC re-renders (body subtree:true + 100ms
  debounce) with an early-return so unchanged state doesn't re-render.
- C-M3 setQuality join-gated; C-M4 hangup 4s fallback dispose (idempotent);
  C-M5 PTT no longer silently un-deafens; C-M6 screenshare-audio mute resets on
  stop; C-L4 deafen key works in the iframe; C-L6 setState-after-unmount guards.

Reviewed (C-H2 [] fail-safe + C-H3 re-render guard applied). tsc/eslint/prettier
clean, build OK, 677 tests.

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

src/app/plugins/call/CallControl.ts

@@ -29,8 +29,22 @@ export class CallControl extends EventEmitter implements CallControlState {
 
   private controlMutationObserver: MutationObserver;
 
+  // C-H3: coalesces bursts of body-subtree mutations into a single debounced
+  // re-observe pass so a busy EC re-render doesn't thrash the control observer.
+  private bodyMutationTimer?: ReturnType<typeof setTimeout>;
+
   private _pipMode = false;
 
+  // C-M3: last quality payload requested via setQuality(). Held so we can (re)send
+  // it once joined (io.lotus.set_quality must not be sent before call-join — a
+  // pre-join send pends to a 10s widget timeout, mirroring the deafen gate).
+  private lastQuality: LotusQualityPayload | null = null;
+
+  // C-M5: set true by CallControls while a push-to-talk key is held. A PTT hold
+  // unmutes the mic transiently, and onMediaState() must NOT treat that as a
+  // user-initiated unmute that auto-undeafens the user.
+  public pttActive = false;
+
   // P6-2: mirrors CallEmbed.joined. Set true from forceState(), which CallEmbed
   // invokes only from onCallJoined(). Gates io.lotus.set_deafen so we never send
   // before the fork's widget handler mounts (pre-join sends pend to a 10s
@@ -153,19 +167,43 @@ export class CallControl extends EventEmitter implements CallControlState {
     // this.joined was still false, so it was gated — this is the first send.)
     this.joined = true;
     this.sendDeafenState();
+    this.sendQuality();
+  }
+
+  /**
+   * C-H1 / C-M3: re-push the sticky fork-side state (deafen + quality) after an
+   * EC reconnect. Unlike forceState() this does NOT touch mic/video, so a
+   * reconnect can't clobber the user's live media state — it only re-arms the
+   * fork handlers that remount on reconnect.
+   */
+  public resendForkState(): void {
+    this.sendDeafenState();
+    this.sendQuality();
   }
 
   public startObserving() {
     if (!this.document) return;
 
+    // C-H3: watch the whole body subtree (not just direct children) so we
+    // re-bind the control observer when EC re-renders its controls deeper in the
+    // tree. Debounced via onBodyMutation() to avoid thrashing on busy renders.
     this.bodyMutationObserver.observe(this.document.body, {
       childList: true,
-      subtree: false, // only direct children of body
+      subtree: true,
     });
-    this.onBodyMutation();
+    this.applyBodyMutation();
   }
 
   private onBodyMutation() {
+    // C-H3: coalesce a burst of subtree mutations into one debounced pass.
+    if (this.bodyMutationTimer !== undefined) return;
+    this.bodyMutationTimer = setTimeout(() => {
+      this.bodyMutationTimer = undefined;
+      this.applyBodyMutation();
+    }, 100);
+  }
+
+  private applyBodyMutation() {
     if (!this.document) return;
 
     this.document.body.style.setProperty('background', 'none', 'important');
@@ -266,22 +304,43 @@ export class CallControl extends EventEmitter implements CallControlState {
     this.state = state;
     this.emitStateUpdate();
 
-    if (this.microphone && !this.sound) {
+    // C-M5: auto-undeafen when the mic turns on, but NOT for a transient
+    // push-to-talk unmute — a PTT tap while deafened must not silently
+    // un-deafen the user.
+    if (this.microphone && !this.sound && !this.pttActive) {
       this.toggleSound();
     }
   }
 
   private onControlMutation() {
+    const wasScreensharing = this.screenshare;
     const screenshare: boolean = this.screenshareButton?.getAttribute('data-kind') === 'primary';
     const spotlight: boolean = this.spotlightButton?.checked ?? false;
 
+    // C-M6: when a screenshare stops, clear the screenshare-audio mute so a
+    // later screenshare doesn't start pre-muted.
+    const screenshareAudioMuted =
+      wasScreensharing && !screenshare ? false : this.screenshareAudioMuted;
+
+    // C-H3: the body observer now watches subtree:true, so this fires on any DOM
+    // churn in EC's controls. Only re-emit (→ re-render every consumer) when one
+    // of the values this method derives actually changed — microphone/video/sound
+    // are copied unchanged from the current state here.
+    if (
+      this.state.screenshare === screenshare &&
+      this.state.spotlight === spotlight &&
+      this.state.screenshareAudioMuted === screenshareAudioMuted
+    ) {
+      return;
+    }
+
     this.state = new CallControlState(
       this.microphone,
       this.video,
       this.sound,
       screenshare,
       spotlight,
-      this.screenshareAudioMuted,
+      screenshareAudioMuted,
     );
     this.emitStateUpdate();
   }
@@ -423,10 +482,25 @@ export class CallControl extends EventEmitter implements CallControlState {
    * clamped fork-side, so out-of-range input can't brick the encoder.
    */
   public setQuality(settings: LotusQualityPayload): void {
-    this.call.transport.send('io.lotus.set_quality', settings).catch(() => undefined);
+    // C-M3: remember the request and only send once joined; sendQuality() gates
+    // on this.joined so a pre-join call is a no-op that we replay on join.
+    this.lastQuality = settings;
+    this.sendQuality();
+  }
+
+  // C-M3: push the last-requested quality to the fork. Gated on this.joined so
+  // we never send io.lotus.set_quality before the fork's handler mounts (a
+  // pre-join send would pend to a 10s widget timeout).
+  private sendQuality(): void {
+    if (!this.joined || !this.lastQuality) return;
+    this.call.transport.send('io.lotus.set_quality', this.lastQuality).catch(() => undefined);
   }
 
   public dispose() {
+    if (this.bodyMutationTimer !== undefined) {
+      clearTimeout(this.bodyMutationTimer);
+      this.bodyMutationTimer = undefined;
+    }
     this.bodyMutationObserver.disconnect();
     this.controlMutationObserver.disconnect();
   }