fix: pass audio/video URL params to EC for correct initial device state

- Camera no longer starts enabled when user disables it in prescreen
- When PTT mode is enabled, call starts muted so PTT works immediately
  without requiring a manual mute first
- CallControlState also updated to match the forced-off audio for PTT

EC 0.16.x ignores io.element.device_mute for initial state at startup,
so audio= and video= URL params are the only reliable way to set the
initial device state before the call begins.

src/app/hooks/useCallEmbed.ts

@@ -45,15 +45,18 @@ export const createCallEmbed = (
   themeKind: ElementCallThemeKind,
   container: HTMLElement,
   pref?: CallPreferences,
-  noiseSuppression = true
+  noiseSuppression = true,
+  forceAudioOff = false
 ): CallEmbed => {
   const rtcSession = mx.matrixRTC.getRoomSession(room);
   const ongoing =
     MatrixRTCSession.sessionMembershipsForRoom(room, rtcSession.sessionDescription).length > 0;
 
   const intent = CallEmbed.getIntent(dm, ongoing);
-  const widget = CallEmbed.getWidget(mx, room, intent, themeKind, noiseSuppression);
+  const initialAudio = forceAudioOff ? false : (pref?.microphone ?? true);
-  const controlState = pref && new CallControlState(pref.microphone, pref.video, pref.sound);
+  const initialVideo = pref?.video ?? false;
+  const widget = CallEmbed.getWidget(mx, room, intent, themeKind, noiseSuppression, initialAudio, initialVideo);
+  const controlState = pref && new CallControlState(forceAudioOff ? false : pref.microphone, pref.video, pref.sound);
 
   const embed = new CallEmbed(mx, room, widget, container, controlState);
 
@@ -66,6 +69,7 @@ export const useCallStart = (dm = false) => {
   const setCallEmbed = useSetAtom(callEmbedAtom);
   const callEmbedRef = useCallEmbedRef();
   const [callNoiseSuppression] = useSetting(settingsAtom, 'callNoiseSuppression');
+  const [pttMode] = useSetting(settingsAtom, 'pttMode');
 
   const startCall = useCallback(
     (room: Room, pref?: CallPreferences) => {
@@ -73,11 +77,11 @@ export const useCallStart = (dm = false) => {
       if (!container) {
         throw new Error('Failed to start call, No embed container element found!');
       }
-      const callEmbed = createCallEmbed(mx, room, dm, theme.kind, container, pref, callNoiseSuppression ?? true);
+      const callEmbed = createCallEmbed(mx, room, dm, theme.kind, container, pref, callNoiseSuppression ?? true, !!pttMode);
 
       setCallEmbed(callEmbed);
     },
-    [mx, dm, theme, setCallEmbed, callEmbedRef, callNoiseSuppression]
+    [mx, dm, theme, setCallEmbed, callEmbedRef, callNoiseSuppression, pttMode]
   );
 
   return startCall;

src/app/plugins/call/CallEmbed.ts

@@ -60,7 +60,9 @@ export class CallEmbed {
     room: Room,
     intent: ElementCallIntent,
     themeKind: ElementCallThemeKind,
-    noiseSuppression = true
+    noiseSuppression = true,
+    initialAudio = true,
+    initialVideo = false
   ): Widget {
     const userId = mx.getSafeUserId();
     const deviceId = mx.getDeviceId() ?? '';
@@ -83,6 +85,8 @@ export class CallEmbed {
       lang: 'en-EN',
       theme: themeKind,
       noiseSuppression: noiseSuppression.toString(),
+      audio: initialAudio.toString(),
+      video: initialVideo.toString(),
     });
 
     const widgetUrl = new URL(