Merge lane base check: develop ffb78d4219d1

Merge lane base check: run the full gate on `develop` at `ffb78d4219d1e8ab8d426dbf0c31eead2cf60fa1` 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.

develop ffb78d4 red (develop_red reported): mirror/community-edition suites fail — apps/api/app/routes/tasks/task_wire.py:94 cites unmirrored docs/policies/repo-access-levels.md, from f689bf9e8 (Task 10710, PR #7161). Memory: none applied.