- Updated ExtractionInfo to include user_id, created_at, and updated_at fields.
- Modified ExtractionService to return user and timestamp information in extraction responses.
- Enhanced sound serialization in PlayerState to include extraction URL if available.
- Adjusted PlaylistRepository to load sound extractions when retrieving playlist sounds.
- Added tests for new fields in extraction and sound endpoints, ensuring proper response structure.
- Created new test file endpoints for sound downloads and thumbnail retrievals, including success and error cases.
- Refactored various test cases for consistency and clarity, ensuring proper mocking and assertions.
