What to connect first. The SPA's "Start here" panel reads load_map from this path; it too existed only on the motherboard front door, so the panel never once rendered on either plane (it hides itself when the list is empty, which is why a 404 here looked like nothing at all).

Aggregate ONLY — connector name and how many waiting steps it would unblock. The backlog rows themselves carry a query string, so they stay server-side and only the count crosses the wire. Missing file -> an empty map plus the path we looked for, never a 500 and never a bare empty list with no reason attached.