List Connector Health Coverage Endpoint

Fleet view of streaming connectors with absent or stale health rows.

The inverse of the list view above: instead of the health rows that exist, this returns the connectors in a live apply state whose declared pgstream deployments have no fresh connector_health_state row — the silent gap where a connector reads healthy by absence of evidence (ARD-1247). missing gaps sort ahead of stale ones. Same verdict the Honeycomb coverage triggers page on, served on demand for the operator console.