fix: harden booking and meeting flows

lib/meeting/livekit.ts

@@ -17,9 +17,9 @@ function getLiveKitApiUrl(): string {
 }
 
 /** Stable opaque room name; the public event slug is never sent to LiveKit logs. */
-export function getLiveKitRoomName(eventSlug: string): string {
+export function getLiveKitRoomName(eventSlug: string, accessVersion?: string): string {
   const secret = requiredEnv("LIVEKIT_API_SECRET");
-  return `anouma-${createHmac("sha256", secret).update(eventSlug).digest("hex").slice(0, 32)}`;
+  return `anouma-${createHmac("sha256", secret).update(JSON.stringify([eventSlug, accessVersion])).digest("hex").slice(0, 32)}`;
 }
 
 export async function createLiveKitToken(args: {
@@ -28,12 +28,18 @@ export async function createLiveKitToken(args: {
   name: string;
   role: MeetingRole;
   clientId?: string;
+  accessVersion?: string;
+  expiresAt: number;
 }): Promise<string> {
-  const room = getLiveKitRoomName(args.eventSlug);
+  const room = getLiveKitRoomName(args.eventSlug, args.accessVersion);
+  const remainingSeconds = Math.floor((args.expiresAt - Date.now()) / 1000);
+  if (remainingSeconds <= 0) throw new Error("Meeting access has expired");
   const token = new AccessToken(requiredEnv("LIVEKIT_API_KEY"), requiredEnv("LIVEKIT_API_SECRET"), {
     identity: args.participantId,
     name: args.name,
-    ttl: "2h",
+    // Self-hosted LiveKit cannot revoke already issued JWTs. Keep the
+    // connection credential short-lived; the app re-authorizes reconnects.
+    ttl: Math.min(60, remainingSeconds),
     metadata: JSON.stringify({ role: args.role, clientId: args.clientId }),
   });
   token.addGrant({