- Add WorkerInstance global singleton for global access
- Add new job types: import, convert, thumbnails, backup, analytics, sync
- Add Enqueue method for non-blocking job submission
- Add job processors for each new job type:
- processImportJob: OPDS and Calibre import support
- processConvertJob: EPUB to KEPUB conversion
- processThumbnailsJob: Cover thumbnail generation
- processBackupJob: Database backup functionality
- processAnalyticsJob: Library and system statistics
- processDirectoryScanJob: Directory scanning for media scanner
- Add helper getTopN function for analytics