Merge lane base check: develop 3111198384f9

Merge lane base check: run the full gate on `develop` at `3111198384f9831987f75fd1e657ec585eaafc8f` 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).

develop 3111198 RED (develop_red reported): 1 deterministic failure, apps/jaahd/tests/test_acp_host.py:728 lambda rejects new question_preamble kwarg from PR #6862 (Task 9893). Fix: `lambda *_a, **_k`. 57,800 other tests green.