- Added `scheduler` package with core functionalities for job scheduling.
- Implemented job registration, execution, and graceful shutdown mechanisms.
- Introduced middleware support for logging, recovery from panics, and timeout handling.
- Developed cron expression parser to support both 5-field and 6-field formats.
- Created comprehensive integration and unit tests for scheduler, job definitions, middleware, and parser functionalities.
- Enhanced logging capabilities to track job execution and errors.