Merge lane base check: develop 950d2a36b88c

Merge lane base check: run the full gate on `develop` at `950d2a36b88c1a7f62cdd597cc36c216fed58084` 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 950d2a36b88c: develop_red reported. Full gate failed twice on vitest CompanySetupCard "Choose plan opens the picker in place…" (companySetupGuide.test.tsx). No PRs queued, nothing ejected. Memory: none applied.