Refactor sound and extraction services to include user and timestamp fields

- 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.

tests/services/test_extraction.py

@@ -175,7 +175,8 @@ class TestExtractionService:
 
     @pytest.mark.asyncio
     async def test_process_extraction_with_service_detection(
-        self, extraction_service,
+        self,
+        extraction_service,
     ) -> None:
         """Test extraction processing with service detection."""
         extraction_id = 1
@@ -314,6 +315,7 @@ class TestExtractionService:
 
                 result = await extraction_service._create_sound_record(
                     audio_path,
+                    None,  # thumbnail_path
                     extraction.title,
                     extraction.service,
                     extraction.service_id,