chore: apply pending code updates

tests/unit/test_parallel_anime_add.py

@@ -5,11 +5,14 @@ each other. The background loader should process multiple series simultaneously
 rather than sequentially.
 """
 import asyncio
+import logging
 from datetime import datetime, timezone
 from unittest.mock import AsyncMock, MagicMock, patch
 
 import pytest
 
+logger = logging.getLogger(__name__)
+
 from src.server.services.background_loader_service import (
     BackgroundLoaderService,
     LoadingStatus,
@@ -162,9 +165,9 @@ async def test_parallel_anime_additions(
         f"(indicating sequential processing)"
     )
     
-    print(f"✓ Parallel execution verified:")
-    print(f"  - Start time difference: {start_diff:.3f}s")
-    print(f"  - Total duration: {total_duration:.3f}s")
+    logger.info("Parallel execution verified")
+    logger.info("Start time difference: %.3fs", start_diff)
+    logger.info("Total duration: %.3fs", total_duration)
 
 
 @pytest.mark.asyncio