- move voice/audio players to single global audio engine with shared volume
- stop/reset previous track when switching to another media
- keep playback alive across chat switches via global audio element
- list refresh sessions by redis scan fallback when user session set is missing
- store refresh session metadata in redis (ip/user-agent/created_at)
- add auth APIs: list sessions, revoke one, revoke all
- add web privacy UI for active sessions