Guest outboxes are append-only from the host's POV — every sweep reads
the same playlist. `applyOutboxSnapshotsToState` was unconditionally
pushing every trackId in every snapshot into `state.queue`, so the
pending-approval list grew by one duplicate per tick for every unhandled
suggestion (visible as 4+ identical rows after ~10 s).
Dedupe against `(user, trackId)` already present in `state.queue` or
`state.currentTrack` before appending. A guest re-suggesting the same
track after it lands/plays is a rare enough case to live with for now.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Psychotoxical
2b1124d14a