Integrate scheduler service into FastAPI lifespan

- Start scheduler service during app startup
- Gracefully stop scheduler during app shutdown
- Track scheduler in initialized services
- Scheduler starts after background loader
- Scheduler shutdown with 5s timeout

src/server/fastapi_app.py

@@ -117,7 +117,8 @@ async def lifespan(_application: FastAPI):
     initialized = {
         'database': False,
         'services': False,
-        'background_loader': False
+        'background_loader': False,
+        'scheduler': False
     }
     
     # Startup
@@ -265,6 +266,18 @@ async def lifespan(_application: FastAPI):
                 initialized['background_loader'] = True
                 logger.info("Background loader service started")
                 
+                # Initialize and start scheduler service
+                from src.server.services.scheduler_service import get_scheduler_service
+                
+                scheduler_service = get_scheduler_service()
+                try:
+                    await scheduler_service.start()
+                    initialized['scheduler'] = True
+                    logger.info("Scheduler service started")
+                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:
@@ -322,7 +335,23 @@ async def lifespan(_application: FastAPI):
         elapsed = time.monotonic() - shutdown_start
         return max(0.0, SHUTDOWN_TIMEOUT - elapsed)
     
-    # 1. Stop background loader service (only if initialized)
+    # 1. Stop scheduler service (only if initialized)
+    if initialized['scheduler']:
+        try:
+            from src.server.services.scheduler_service import get_scheduler_service
+            scheduler_service = get_scheduler_service()
+            logger.info("Stopping scheduler service...")
+            await asyncio.wait_for(
+                scheduler_service.stop(),
+                timeout=min(5.0, remaining_time())
+            )
+            logger.info("Scheduler service stopped")
+        except asyncio.TimeoutError:
+            logger.warning("Scheduler service shutdown timed out")
+        except Exception as e:  # pylint: disable=broad-exception-caught
+            logger.error("Error stopping scheduler service: %s", e, exc_info=True)
+    
+    # 2. Stop background loader service (only if initialized)
     if initialized['background_loader']:
         try:
             from src.server.utils.dependencies import _background_loader_service
@@ -338,7 +367,7 @@ async def lifespan(_application: FastAPI):
         except Exception as e:  # pylint: disable=broad-exception-caught
             logger.error("Error stopping background loader service: %s", e, exc_info=True)
     
-    # 2. Broadcast shutdown notification via WebSocket
+    # 3. Broadcast shutdown notification via WebSocket
     try:
         ws_service = get_websocket_service()
         logger.info("Broadcasting shutdown notification to WebSocket clients...")
@@ -352,7 +381,7 @@ async def lifespan(_application: FastAPI):
     except Exception as e:  # pylint: disable=broad-exception-caught
         logger.error("Error during WebSocket shutdown: %s", e, exc_info=True)
     
-    # 3. Shutdown download service and persist active downloads
+    # 4. Shutdown download service and persist active downloads
     try:
         from src.server.services.download_service import (  # noqa: E501
             _download_service_instance,