fix(livekit): stable identity + room auto-cleanup

Use the member name as the LiveKit identity (was random per join) so a
refresh/rejoin replaces the existing session instead of leaving a ghost
participant in the room. Set roomConfig on the token (emptyTimeout 60s,
departureTimeout 20s) so empty rooms and departed participants clean up
promptly. Pods map 1:1 to a deterministic room name, so joins reuse the
same room rather than spawning new ones.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/src/server.ts

@@ -2,7 +2,7 @@ import express from 'express';
 import cors from 'cors';
 import { createServer } from 'node:http';
 import { WebSocketServer } from 'ws';
-import { AccessToken } from 'livekit-server-sdk';
+import { AccessToken, RoomConfiguration } from 'livekit-server-sdk';
 import { env } from './env.js';
 import { createSyncPr } from './github/client.js';
 import { recordOutcome, memoryStats } from './memory/store.js';
@@ -36,6 +36,9 @@ app.post('/api/token', async (req, res) => {
     metadata: JSON.stringify({ githubLogin: githubLogin ?? name }),
   });
   at.addGrant({ roomJoin: true, room, canPublish: true, canSubscribe: true, canPublishData: true });
+  // Auto-clean the room: close 60s after it empties, drop a participant 20s
+  // after they disconnect. Applied when LiveKit auto-creates the room.
+  at.roomConfig = new RoomConfiguration({ name: room, emptyTimeout: 60, departureTimeout: 20 });
   res.json({ token: await at.toJwt(), url: env.LIVEKIT_URL });
 });
 

frontend/src/App.tsx

@@ -47,7 +47,9 @@ export default function App() {
 
   // Connect to a pod's LiveKit room and persist the session for refresh-resume.
   async function connectToPod(podId: string, who: string) {
-    const identity = `${who}-${Math.random().toString(36).slice(2, 7)}`;
+    // Stable identity per member so a refresh/rejoin replaces the existing
+    // session instead of leaving a ghost participant behind.
+    const identity = who;
     const result = await joinPod(podId, identity, who);
     setRoom(result.room);
     setDevMode(result.mode === 'dev');