Merge lane base check: develop 7e85629e2084

Merge lane base check: run the full gate on `develop` at `7e85629e2084d8fe10c381665de9b9ed0ccb89ba` 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 (Task 6722).

Base check develop 7e85629e2084: RED (reported develop_red). Full gate 55060 pass / 3 fail, failures reproduce in isolation: e2e org-limits.spec:14, products-tabs-mobile.spec:13, project-create-placement.spec:10. No merges; fix task filed by CP.