Merge lane base check: develop 9ef2be6b483c

Merge lane base check: run the full gate on `develop` at `9ef2be6b483ce33c49eceb0ea3db85c40acd0c88` 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 9ef2be6b reported develop_red (full gate 2×, 3 mirror/community-edition stages): 'Task 6033' internal reference in apps/web/src/pages/nodes/hosts/hostVerbs.tsx:230 (commit 25b54081f) trips the mirror sensitive-content scan. No PRs ejected.