fixes and improvements

backend/src/media_library_viewer_api/routers/monitoring.py

@@ -53,8 +53,8 @@ def _resolve_machine(store: SettingsStore, machine_id: str | None) -> dict[str,
 
 @router.get("/machines")
 def get_machines(store: SettingsStore = Depends(get_settings_store)) -> list[dict[str, Any]]:
-    """Return monitoring machines for the UI."""
-    return store.list_machines()
+    """Return enabled monitoring machines for the UI."""
+    return [m for m in store.list_machines() if m.get("enabled")]
 
 
 @router.get("/poller")