Merge lane base check: develop 4bcc928ba281

Merge lane base check: run the full gate on `develop` at `4bcc928ba281f62b6850377e26d69f26393bda80` alone and report it certified or red: nothing had certified it since the last attempt. A red verdict files a fix task; it never holds the lane. Filed by the control plane (`app/merge_lane.py::_certify_idle`). How: run `python3 tools/merge_lane.py run` once. It takes this check's batch, gates that commit with the full gate in its sandbox and reports `certified` or `develop_red` itself. Never run the gate by hand: a hand-run green reports nothing, so no certificate is recorded.

Base check 4bcc928: develop_red — test_tenant_gmail allowlist missed ses_inbound.py (from 006492d72, Task 10762); already fixed forward by c28916ac5 (Task 10788, PR #7183). Nothing ejected. Memory: none applied.