fix: Fix multiple bugs with new authentication flow

toju-app/src/app/domains/voice-session/README.md

@@ -82,6 +82,16 @@ When a voice session is active and the user navigates away from the voice-connec
 
 Joining a new voice target is exclusive: entering another voice channel or private call first disconnects the current call/channel, clears local voice state, and broadcasts the leave for the previous target. Users never need to manually leave one voice target before joining another.
 
+## Multi-device voice (Discord-style)
+
+Each install has a stable `clientInstanceId` (`ClientInstanceService`). `VoiceState.clientInstanceId` records which device currently owns the microphone/WebRTC session for that user.
+
+- **Local voice owner** — this device's `clientInstanceId` matches `voiceState.clientInstanceId`; mic, heartbeat, and WebRTC transmit run normally.
+- **Passive client** — another device owns voice; this client still receives chat/presence and shows grayed "in voice on another device" UI in the room sidebar and private-call cards.
+- **Takeover** — clicking **Join** on a passive client sends `voice_client_takeover` through signaling; the active device releases voice via `VoiceClientTakeoverService`, then the passive client completes a normal join.
+
+Rules live in `domain/logic/client-voice-session.rules.ts`.
+
 Remote voice playback is scoped to the active voice channel, not the whole server. Users stay connected to the shared peer mesh for text, presence, and screen-share control, but voice transport and playback only stay active for peers whose `voiceState.roomId` and `voiceState.serverId` match the local user's current voice session.
 
 Owners and admins can also move connected users between voice channels from the room sidebar by dragging a user onto a different voice channel. The moved client updates its local heartbeat and voice-session metadata to the new channel, so routing, floating controls, and occupancy stay in sync after the move.