Merge lane base check: develop ba1c58c45e3a

Merge lane base check: run the full gate on `develop` at `ba1c58c45e3a4d6771a3b9c50d6604091bd0b011` 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 ba1c58c45e3a: develop_red (reported by merge_lane.py run, gate 2×). 3 e2e failures (company-setup plan label, org-switcher self-create, project-memory unknown setting) — likely Task 8710 plan pane. Fix task #8834 active. Memory: none applied.