Add NFO batch operations unit tests

- Created tests/unit/test_nfo_batch_operations.py
  * 19 comprehensive unit tests all passing
  * Test concurrent operations with max_concurrent limits
  * Test partial failure handling (continues processing)
  * Test skip_existing and overwrite functionality
  * Test media download options
  * Test result accuracy and error messages
  * Test edge cases (empty, single, large, duplicates)

- Updated docs/instructions.md
  * Marked NFO batch operations tests as completed
  * Documented 19/19 passing tests

src/server/services/scheduler_service.py

@@ -232,8 +232,8 @@ class SchedulerService:
             logger.info("Starting scheduled library rescan")
             
             # Import here to avoid circular dependency
-            from src.server.utils.dependencies import get_anime_service
             from src.server.services.websocket_service import get_websocket_service
+            from src.server.utils.dependencies import get_anime_service
             
             anime_service = get_anime_service()
             ws_service = get_websocket_service()