- Extract rescan logic into new RescanService (src/server/services/rescan_service.py)
- SchedulerService now only handles APScheduler cron scheduling
- Move scheduler sub-services (folder_rename, folder_scan, key_resolution) to scheduler/ folder
- Keep RescanOrchestrator as backward-compatible alias
- Update all imports across api/, server/, and test files
✅ COMPLETE: 18/18 tests passing
Test Coverage:
- Concurrent scan prevention: Second scan blocked, multiple attempts handled, lock released after completion
- Scan cancellation: Cancel active scan, cancel when none active, cancelled scans in history, new scan after cancellation
- Database race conditions: AsyncIO lock prevents races, scan state consistency with concurrent reads, thread-safe history updates
- Scan state consistency: is_scanning flag consistency, current_scan object consistency, status API consistency, concurrent status checks
- Scheduler prevention: Scheduler skips rescan if already running, properly sets scan_in_progress flag
- AnimeService: Ignores concurrent rescan requests
All concurrent operation scenarios validated with proper lock management and state consistency.
