Fix: Load series from DB on startup and save missing episodes when adding series

src/server/fastapi_app.py

@@ -145,6 +145,12 @@ async def lifespan(_application: FastAPI):
                     "Data file sync complete. Added %d series.", sync_count
                 )
                 
+                # Load series from database into SeriesApp's in-memory cache
+                from src.server.utils.dependencies import get_anime_service
+                anime_service = get_anime_service()
+                await anime_service._load_series_from_db()
+                logger.info("Series loaded from database into memory")
+                
                 # Now initialize download service (will use data from database)
                 from src.server.utils.dependencies import get_download_service
                 download_service = get_download_service()