Function handle_delete_map_key 

pub async fn handle_delete_map_key(
    __arg0: State<AppState>,
    headers: HeaderMap,
    __arg2: Query<MapKeyQuery>,
) -> Response

DELETE /api/config/map-key?path=<section>&key=<alias> — remove an alias from a map-keyed section. Aliased config sections with executable delete support route through the same cascade engine as the delete preview; non-aliased sections keep the generic raw key removal. Persists on success.