feat: implement persistent audit logging for import/export operations with Prometheus metrics

monitoring/__init__.py

@@ -0,0 +1,13 @@
+from __future__ import annotations
+
+from fastapi import APIRouter, Response
+from prometheus_client import CONTENT_TYPE_LATEST, generate_latest
+
+
+router = APIRouter(prefix="/metrics", tags=["monitoring"])
+
+
+@router.get("", summary="Prometheus metrics endpoint", include_in_schema=False)
+async def metrics_endpoint() -> Response:
+    payload = generate_latest()
+    return Response(content=payload, media_type=CONTENT_TYPE_LATEST)