Merge lane base check: develop e1d6b2045e98

Merge lane base check: run the full gate on `develop` at `e1d6b2045e98e575782ec04be555f32fc61aaac8` 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 e1d6b2045e98 certified green via merge_lane.py run (full gate 671s, 57754 passed, 0 failed; tree 1438f40859). Nothing merged or ejected; queue empty, no breaches. Memory: none applied.