Video track does not fall back to default device on TrackEnded, unlike audio #2035

Describe the bug

In LocalParticipant.handleTrackEnded, when a device disconnects (e.g. an external webcam is unplugged) and the corresponding MediaStreamTrack fires ended, the SDK explicitly falls back to the default device for audio tracks, but not for video tracks:

https://github.com/livekit/client-sdk-js/blob/v2.21.0/src/room/participant/LocalParticipant.ts#L2126-L2132

if (isLocalAudioTrack(track)) {
  // fall back to default device if available
  await track.restartTrack({ deviceId: 'default' });
} else {
  await track.restartTrack();
}

For video, restartTrack() is called with no override, so it retries against the same (now-disconnected) deviceId constraint, fails again, and the surrounding catch mutes the track instead of falling back:

} catch (e) {
  this.log.warn(`could not restart track, muting instead`, getLogContextFromTrack(track));
  await track.mute();
}

The result: unplugging an external microphone falls back seamlessly to the default mic, but unplugging an external webcam just turns the camera off, even though a built-in/default camera is available.

I confirmed this is still present, unchanged, on the latest release (v2.21.0) — same if (isLocalAudioTrack(track)) check, no equivalent branch for isLocalVideoTrack(track).

Reproduction

1. Join a room with an external webcam selected as the camera source.
2. Physically disconnect the webcam.
3. Observe: the local video track ends and gets muted (camera turns off), instead of falling back to the default/built-in camera the way an external microphone falls back to the default mic in the same scenario.

Expected behavior

When a video track ends due to a device disconnect (and the track is not user-muted), it should retry restartTrack({ deviceId: 'default' }), mirroring the existing audio behavior, so the camera falls back to the default device instead of going dark.

Suggested fix

if (isLocalAudioTrack(track) || isLocalVideoTrack(track)) {
  // fall back to default device if available
  await track.restartTrack({ deviceId: 'default' });
}

(Since this branch is only reached when isLocalAudioTrack(track) || isLocalVideoTrack(track) is already true per the outer else if, this can also simply be unconditional.)

Reproduction repo/live example

N/A — traced directly in the SDK source while debugging camera-off behavior in our app; happy to share more details if useful.

SDK version

livekit-client 2.15.14 through 2.21.0 (latest at time of filing)