### Fixed

- **_execute_task Enhancements:** 'AsyncExecutionQueue'
  - Added a callback to check and log unconsumed exceptions by calling `handle_future_exception()` with a 0.1-second delay.
  - Integrated the `chain_future_results()` helper function as a callback to propagate the result or exception to the target `task_future`.

- **Worker Exception Handling:**
  - Enhanced the `worker()` method to include exception handling around task execution, ensuring that any issues during task processing are properly caught and handled.

- **Graceful Shutdown Improvements:**
  - Updated the `aclose()` method to cancel all tasks waiting in the queue before signaling the worker to exit, ensuring that no pending tasks remain unprocessed during shutdown.

- Resolved issue with `copy_context()` loss when passing messages via the
`AsyncExecutionQueue`.