Also fix camera reloading in widget mode

src/room/LobbyView.tsx

@@ -184,6 +184,16 @@ export const LobbyView: FC<Props> = ({
         null) as LocalVideoTrack | null,
     [tracks],
   );
+
+  useEffect(() => {
+    if (videoTrack && videoInputId === undefined) {
+      // If we have a video track but no videoInputId,
+      // we have to update the available devices. So that we select the first
+      // available video input device as the default instead of the `""` id.
+      devices.requestDeviceNames();
+    }
+  }, [devices, videoInputId, videoTrack]);
+
   useTrackProcessorSync(videoTrack);
   const showSwitchCamera = useShowSwitchCamera(
     useObservable(

src/state/MediaDevices.ts

@@ -355,6 +355,9 @@ export class MediaDevices {
    * available device, rather than numbered identifiers. This may invoke a
    * permissions pop-up, so it should only be called when there is a clear user
    * intent to view the device list.
+   *
+   * This always updates the `available$` devices for each media type with the current value
+   * of `enumerateDevices`.
    */
   public requestDeviceNames(): void {
     void navigator.mediaDevices.enumerateDevices().then((result) => {