Merge lane base check: develop 2e2caff8fe81

Merge lane base check: run the full gate on `develop` at `2e2caff8fe810c5401b1de46e7ac27c3db1fac8e` 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 2e2caff8fe81: RED (develop_red reported). Full gate 55268 pass/2 fail in frontend smoke; both failed again alone: access-principal.spec.ts:116, self-service-onboarding.spec.ts:51. Fix task via CP. Memory: none applied.