feat(vibe): reconcile mutable session previews in playback

docker-compose.yml

@@ -32,6 +32,10 @@ services:
       TYPESENSE_API_KEY: ${TYPESENSE_API_KEY}
       MUZICK_API_KEY: ${MUZICK_API_KEY}
       MUZICK_ADMIN_KEY: ${MUZICK_ADMIN_KEY}
+      # Durable Vibe sessions are intentionally bound to this configured,
+      # server-trusted owner instead of accepting a client-supplied user id.
+      # Set it to the UUID of the local Muzick user in .env.
+      MUZICK_VIBE_USER_ID: ${MUZICK_VIBE_USER_ID}
       MUSIC_DIR: /music
     volumes:
       # READ-ONLY, deliberately. Nothing in the API request path may write to