Function metrics_webhooks_handler 

pub async fn metrics_webhooks_handler(__arg0: State<WebhookIngress>) -> Response

GET /api/console/metrics/webhooks — oldest-pending-age as a health state.

Why: ADR-0034 §2 requires the signal on console’s existing metrics surface, red once a delivery has been pending too long. What: scans the spool on this request and returns a ConsoleMetricsReport. Always 200, never 503: a red report is information, and a 503 would be indistinguishable from “no data yet” — which is the fail-quiet reading this signal exists to prevent. Test: metrics_route_reports_red_for_an_aged_pending_entry, metrics_route_reports_ok_on_an_empty_spool.