Merge lane base check: develop cf2280f5b8bf

Merge lane base check: run the full gate on `develop` at `cf2280f5b8bf98f41f7ed124505976ea0e649a41` 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 develop cf2280f5b8bf: red. e2e/project-repos-table.spec.ts:84 (32-char owner/name ≤2 lines at 1366px) fails deterministically, including on a focused rerun. develop_red reported by the lane; no PR ejected.