feat: add legacy key/data file migration to database

- Add migration_legacy_files_completed flag to SystemSettings model
- Create legacy_file_migration service to migrate series from key/data files
- Integrate legacy migration into initialization_service startup flow
- Add integration tests for legacy file migration
- Update DATABASE.md documentation with migration details
- Fix various test and service issues (nfo_repair, tmdb_client, download_service)
- Add test_database_schema unit tests

src/server/fastapi_app.py

@@ -398,21 +398,6 @@ async def lifespan(_application: FastAPI):
                 except Exception as e:
                     logger.warning("Failed to start background loader service: %s", e)
 
-                # Initialize and start scheduler service
-                try:
-                    logger.info("Initializing scheduler service...")
-                    from src.server.services.scheduler_service import (
-                        get_scheduler_service,
-                    )
-                    scheduler_service = get_scheduler_service()
-                    logger.info("Scheduler service instance obtained, starting...")
-                    await scheduler_service.start()
-                    initialized['scheduler'] = True
-                    logger.info("Scheduler service started successfully")
-                except Exception as e:
-                    logger.warning("Failed to start scheduler service: %s", e)
-                    # Continue - scheduler is optional
-
                 # Run media scan only on first run
                 await perform_media_scan_if_needed(background_loader)
             else:
@@ -420,6 +405,22 @@ async def lifespan(_application: FastAPI):
                     "Download service initialization skipped - "
                     "anime directory not configured"
                 )
+
+            # Initialize and start scheduler service (independent of anime_directory)
+            # The scheduler loads its own config from config.json and the
+            # anime_directory may be configured there even if the env var is empty.
+            try:
+                logger.info("Initializing scheduler service...")
+                from src.server.services.scheduler_service import (
+                    get_scheduler_service,
+                )
+                scheduler_service = get_scheduler_service()
+                logger.info("Scheduler service instance obtained, starting...")
+                await scheduler_service.start()
+                initialized['scheduler'] = True
+                logger.info("Scheduler service started successfully")
+            except Exception as e:
+                logger.warning("Failed to start scheduler service: %s", e)
         except (OSError, RuntimeError, ValueError) as e:
             logger.warning("Failed to initialize services: %s", e)
             # Continue startup - services can be initialized later