- Add broadcastOpusToWeb to PcmBroadcaster interface for raw Opus packets
- Server broadcasts Opus frames with mode byte (1) + user hash + packet data
- Browser detects packet mode: mode=1 for Opus, mode=0 for legacy PCM
- Implement WebCodecs AudioDecoder for Opus decoding in browser
- Keep existing PCM playback as fallback for compatibility
- Show error if WebCodecs unsupported
- Fixes listen feature under Bun where native Opus decode unavailable
