- Add _cleanup_orphaned_crontab() helper function
- Delete old crontab when disabling backup schedule
- Delete old crontab when schedule settings change
- Prevents database bloat from unused CrontabSchedule records
- Set CrontabSchedule timezone to system timezone for accurate scheduling
- Replace time TextInput with hour/minute Select dropdowns for cleaner UX
- Remove UTC/local time conversion logic (handled by Celery)
- Add tests for timezone functionality in simple and advanced modes
Frontend changes:
- Add advanced mode toggle switch for cron expressions
- Show cron expression input with helpful examples when enabled
- Display format hints: "minute hour day month weekday"
- Provide common examples (daily, weekly, every 6 hours, etc.)
- Conditionally render simple or advanced scheduling UI
- Support switching between simple and advanced modes
Backend changes:
- Add cron_expression to schedule settings (SETTING_KEYS, DEFAULTS)
- Update get_schedule_settings to include cron_expression
- Update update_schedule_settings to handle cron_expression
- Extend _sync_periodic_task to parse and use cron expressions
- Parse 5-part cron format: minute hour day_of_month month_of_year day_of_week
- Create CrontabSchedule from cron expression or simple frequency
- Add validation and error handling for invalid cron expressions
This addresses maintainer feedback for "custom scheduler (cron style) for more control".
Users can now schedule backups with full cron flexibility beyond daily/weekly.
