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/hooks/useWebSocket.ts

@@ -25,6 +25,14 @@ function handleEvent(event: ServerEvent): void {
       if (currentServerId) {
         loadServerDetail(currentServerId);
       }
+      // Populate voice channel state so users see who's in voice on load
+      if ((event as any).voiceStates) {
+        const vs = (event as any).voiceStates as Record<string, string[]>;
+        const { setVoiceUsers } = useVoiceStore.getState();
+        for (const [channelId, userIds] of Object.entries(vs)) {
+          setVoiceUsers(channelId, userIds);
+        }
+      }
       break;
 
     case 'message_created':