fix: remove orphaned docstring fragment causing syntax error

- Remove misplaced 'Returns:' section and return statement outside method
- Fix unterminated triple-quoted string literal error
- Method scan_and_process_nfo doesn't return a value, so removed incorrect docstring

src/core/services/series_manager_service.py

@@ -235,7 +235,7 @@ class SeriesManagerService:
         # Import database dependencies
         from src.server.database.connection import get_db_session
         from src.server.database.service import AnimeSeriesService
-        
+
         # Load series from database (not from filesystem)
         async with get_db_session() as db:
             anime_series_list = await AnimeSeriesService.get_all(
@@ -272,11 +272,6 @@ class SeriesManagerService:
             # Small delay between batches to respect rate limits
             if i + batch_size < len(tasks):
                 await asyncio.sleep(2)
-        
-        Returns:
-            SerieList instance
-        """
-        return self.serie_list
     
     async def close(self):
         """Clean up resources."""