- Added a global exception handler to log unhandled exceptions and return a generic 500 JSON response without exposing details to the client.
- Updated the configuration to validate the `DATABASE_URL` format, ensuring it starts with `sqlite://` or `postgresql://`, and log warnings for invalid formats.
- Introduced safe parsing for numeric environment variables (`HTTP_PORT`, `INIT_DATA_MAX_AGE_SECONDS`) with defaults on invalid values, including logging warnings for out-of-range values.
- Enhanced the duty schedule parser to enforce limits on the number of schedule rows and the length of full names and duty strings, raising appropriate errors when exceeded.
- Updated internationalization messages to include generic error responses for import failures and parsing issues, improving user experience.
- Added unit tests to verify the new error handling and configuration validation behaviors.
- Introduced new tests for the `import_duty_schedule_cmd` to verify behavior when no message or effective user is present, ensuring proper early returns.
- Added tests for admin checks to confirm that only authorized users can initiate duty schedule imports, enhancing security.
- Implemented error handling tests for the `handle_handover_time_text` function to ensure appropriate responses for invalid time formats and non-admin users.
- Enhanced overall test coverage for the duty schedule import functionality, contributing to improved reliability and maintainability of the codebase.
- Updated the `.coverage` file to reflect the latest coverage metrics.
