Merge lane base check: develop fae2dc34f091

Merge lane base check: run the full gate on `develop` at `fae2dc34f0911477441c377fe120b60e87f8b81a` 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 fae2dc34f091: certified — full gate green (64,879 passed, 0 failed, 836s), tree 2bcfb40f90. Nothing ejected; develop green. Memory: none applied.