Interface QueuedSend

One send queued while offline (see the queueOffline option) — replayed FIFO by flushOutbox with its ORIGINAL turnId (the server's turn-dedup is what makes the retry safe). at is Date.now() at enqueue.

unsent (0.39.0, CR-140) records whether the send provably NEVER reached the server: true when navigator.onLine was already false (the request was never made), so the replay runs the turn exactly once at ANY age. Absent/false = AMBIGUOUS — a dispatch was attempted and failed at the network level (or a stream dropped mid-flight), so the turn MAY have run server-side; flushOutbox only auto-replays these while they are younger than OUTBOX_AMBIGUOUS_MAX_AGE_MS (past that the server may have forgotten the turnId and a replay would double-run it).