Reserve the actively delivered outbox event while the external sender is pending so concurrent persistence cannot evict it through expiry or capacity enforcement. Apply the delivery outcome under the exclusive chain before normal cleanup resumes, preserving retry state, delivery acknowledgements, and cooldown timing without duplicate sends. Add deterministic concurrency regressions for expiry-success and capacity-failure races.
Enforce one shared shutdown deadline while persisting late digests during blocked sends. Start stall cooldowns from serialized delivery acknowledgements, atomically rewrite cleaned legacy outboxes, retain run summaries for 24 hours, and prevent duplicate history or synthetic post-process start times.
Sucukdeluxe