feat(observability): add Prometheus/Grafana/Loki/Alertmanager/Alloy stack and remove legacy Monitoring UI

backend/src/media_library_viewer_api/routers/media.py

@@ -16,6 +16,7 @@ from fastapi import APIRouter, Depends, HTTPException, Query, status
 
 from media_library_viewer_api.clients.jellyfin import JellyfinClient
 from media_library_viewer_api.dependencies import get_jellyfin_client, get_user_id
+from media_library_viewer_api.observability import record_media_index_build
 from media_library_viewer_api.services.media_index import MediaIndex
 
 logger = logging.getLogger(__name__)
@@ -169,6 +170,7 @@ def post_build_index(
             },
         )
         media_status = index.status()
+    record_media_index_build(status="started")
     logger.info("Media index build started pid=%s", process.pid)
     return {"status": "started", **_serialize_status(media_status)}
 
@@ -256,6 +258,7 @@ def force_stop_build(index: MediaIndex = Depends(get_media_index)) -> dict[str,
             },
         )
         media_status = index.status()
+    record_media_index_build(status="force_stopped")
     return {"status": "force_stopped", **_serialize_status(media_status)}