Add a new shared-music feature that allows users to share YouTube or
direct audio URLs with all participants. Music plays locally on each
device with the host controlling playback (play/pause/seek/volume).
New feature module includes:
- Redux state management (actions, reducer, middleware)
- Conference command sync for real-time playback coordination
- YouTube player (hidden video, audio only) via react-youtube
- HTML5 audio player for direct audio URLs
- Toolbar button with share dialog
- Translation strings for all UI elements
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Jeff Emmett