Merge lane base check: develop 1c4ac7e29422

Merge lane base check: run the full gate on `develop` at `1c4ac7e29422fb898a942338bdb6a9ecd0b87590` 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.

develop 1c4ac7e29422 red (lane reported develop_red, 2 runs, 4 fails): session_summary.py:40-41 comment names 'Task 10933'/'Task 10947' (f8055b4ae5, PR #7219), tripping the jaah-ce mirror tracking scan. Fix: drop the task numbers. Memory: none applied