- Created DataExportService for comprehensive user data export (GDPR compliance)
- Exports all user data: profile, settings, tracks, playlists, comments, likes, analytics, federated identities, roles
- Added ExportUserData method to retrieve all user data from database
- Added ExportUserDataAsJSON method to export as downloadable JSON file
- Added endpoint GET /api/v1/users/me/export that returns JSON file download
- Comprehensive unit tests for export service
- Proper error handling and logging
Phase: PHASE-6
Priority: P2
Progress: 118/267 (44.19%)
