fix: resolve LiveKit voice/video stability issues

- Guard Disconnected/ConnectionStateChanged event handlers against stale rooms:
  old room events no longer nuke the new room's state (root cause of buttons
  failing, mute getting stuck, DUPLICATE_IDENTITY cascades)
- Reset media state (isMuted/isCameraOn/isScreenSharing) on connect to prevent
  desync after reconnects
- Add voiceStates to WS ready payload so users see who's in voice on page load
- Wire VoiceControls buttons to check getActiveRoom() before SDK calls
- Guard ChannelSidebar against re-joining the same voice channel
- Switch LIVEKIT_URL to wss://nova.ddns.net/livekit for HTTPS secure context
  (required for getUserMedia in Safari)

packages/web/src/components/voice/VoiceUser.tsx

@@ -1,5 +1,6 @@
 import React, { useRef, useEffect } from 'react';
 import { Avatar } from '../ui/Avatar';
+import { useVoiceStore } from '../../stores/voiceStore';
 import type { ParticipantInfo } from '../../hooks/useLiveKit';
 
 interface VoiceUserProps {
@@ -9,6 +10,7 @@ interface VoiceUserProps {
 export function VoiceUser({ participant }: VoiceUserProps) {
   const videoRef = useRef<HTMLVideoElement>(null);
   const audioRef = useRef<HTMLAudioElement>(null);
+  const isDeafened = useVoiceStore((s) => s.isDeafened);
 
   useEffect(() => {
     const videoEl = videoRef.current;
@@ -31,6 +33,14 @@ export function VoiceUser({ participant }: VoiceUserProps) {
     audioEl.srcObject = stream;
   }, [participant.audioTrack]);
 
+  // Mute remote audio when deafened
+  useEffect(() => {
+    const audioEl = audioRef.current;
+    if (audioEl) {
+      audioEl.muted = isDeafened;
+    }
+  }, [isDeafened]);
+
   const hasVideo = participant.isCameraOn || participant.isScreenSharing;
   const isLocal = participant.isLocal;