fix: Anime list endpoint now returns data correctly

- Root cause: Server needed restart to complete initialization
- Startup process syncs data files to DB and loads into memory
- Verified: GET /api/anime returns 192 anime with full metadata

tests/unit/test_background_loader_optimization.py

@@ -462,7 +462,7 @@ class TestPerformanceComparison:
     async def test_scan_single_series_is_fast(self, background_loader, tmp_path):
         """Test that scanning a single series is fast."""
         import time
-        
+
         # Create series structure
         series_dir = tmp_path / "Performance Test"
         for season_num in range(1, 6):