Merge lane base check: develop a294f2458557

Merge lane base check: run the full gate on `develop` at `a294f2458557c7a86986dcb5f69190c158a3244e` 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 a294f2458557: RED (develop_red reported by merge_lane.py run). operator-dashboard.spec.ts:265 fails in full gate twice, passes alone — load-sensitive. Nothing merged/ejected; fix task filed by CP. Memory: none applied.