Offline Behavior
What a screen does when the network drops, and what happens when it comes back.
A paired player keeps its last manifest and cached media in IndexedDB / the Service Worker cache. If the network drops, it keeps playing. The grace period is 7 days; after that, the screen falls back to the offline interstitial.
On reconnect, the player picks up where it left off, syncs queued play events to the server in batches, and revalidates the manifest ETag. No manual intervention is needed.