Merge lane base check: develop 82429f789e5c

Merge lane base check: run the full gate on `develop` at `82429f789e5c7e0e9760f6b02eb3f2e9c49fe316` 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 82429f789e5c: develop_red (full gate red 2×: vitest Typography colour test + API credential-tester/ifttt/cross-org/nodevault/outbox tests). Lane reported it; fix task filed by CP. Nothing ejected. Memory: none applied.