Implement comprehensive schedule management service for automated scans:
New Files:
- web/services/schedule_service.py (470 lines)
* Complete CRUD operations for schedules
* Cron expression validation using croniter
* Next run time calculation
* Execution history tracking
* Human-readable relative time formatting
- tests/test_schedule_service.py (671 lines, 40+ tests)
* Create/get/list/update/delete schedule tests
* Cron validation and next run calculation tests
* Pagination and filtering tests
* Schedule history and serialization tests
Changes:
- requirements-web.txt: Add croniter==2.0.1 dependency
- docs/ai/PHASE3.md: Mark Step 1 complete, Step 2 next
Key Features:
- Validates cron expressions before saving
- Automatically calculates next execution time
- Preserves historical scans when schedules deleted
- Supports pagination and filtering by enabled status
- Provides relative time display (e.g., "in 2 hours")