- Add onVoicePcmData and onVoiceActiveUser handlers to WebSocket interface
- Add voice_pcm_data and voice_active_user event cases in socket message handler
- Update useAudioPlayback to decode base64 PCM from JSON format
- Connect onVoicePcmData to audio.handleIncomingPcm in App.tsx
Format change:
- Old: Binary (4 bytes userId + PCM buffer)
- New: JSON {userId: string, pcm: base64string}
This matches the format sent by discord-gateway via Redis.
Now PCM audio will flow correctly: Discord → Gateway → Redis → Backend → WebSocket → Browser!
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>