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/features/call/CallSoundboard.tsx

@@ -1,4 +1,4 @@
-import React, { MouseEventHandler, useCallback, useMemo, useState } from 'react';
+import React, { MouseEventHandler, useCallback, useEffect, useMemo, useRef, useState } from 'react';
 import {
   Box,
   Icon,
@@ -64,6 +64,16 @@ export function CallSoundboard({ callEmbed }: CallSoundboardProps) {
   const [playingKey, setPlayingKey] = useState<string>(); // host-side spam guard
   const [error, setError] = useState<string>();
 
+  // C-L6: the play() flow schedules a 30s safety timeout that clears playingKey;
+  // guard those setState calls against the component unmounting first.
+  const mountedRef = useRef(true);
+  useEffect(
+    () => () => {
+      mountedRef.current = false;
+    },
+    [],
+  );
+
   const groups = useMemo(
     () =>
       packs
@@ -86,7 +96,10 @@ export function CallSoundboard({ callEmbed }: CallSoundboardProps) {
       if (playingKey) return; // one at a time (fork also enforces this)
       setPlayingKey(flat.key);
       setError(undefined);
-      const done = () => setPlayingKey((k) => (k === flat.key ? undefined : k));
+      const done = () => {
+        if (!mountedRef.current) return;
+        setPlayingKey((k) => (k === flat.key ? undefined : k));
+      };
       try {
         const url = await resolveClipObjectUrl(mx, flat.clip.url);
         const vol = (flat.clip.volume / 100) * master;