Merge lane base check: develop 8de1b5831771

Merge lane base check: run the full gate on `develop` at `8de1b58317710aaa318b5b0ad6877065495ff553` 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 8de1b5831771: develop_red (reported by merge_lane.py run). 8 API tests fail, reproduced alone: 6 test_console_places operator-only guard mismatches + 2 plan-migration runner_slots caps. Likely PR #6516. Nothing merged. Memory: none applied.