- Wrapped queue shutdown and cancel test assertions in `try`/`finally` blocks.
- Cancelled and awaited worker and in-flight tasks in finalizers to prevent lingering background tasks.
- Handled expected `CancelledError` exceptions during task cleanup with `suppress`.
- Added event retry settings with parsed delay schedules and jittered delay computation.
- Extended event persistence to persist an `available_at` timestamp, honor it during dequeuing, and clear it when re-queuing.
- Updated worker failure handling to queue bounded retries with backoff and transition to failed only when the retry budget is exhausted.