Merge lane base check: develop ad0f8f1ee3f5

Merge lane base check: run the full gate on `develop` at `ad0f8f1ee3f5f0ba1a61e8633b6d8b556d428100` 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 ad0f8f1: develop_red (reported by merge_lane.py run). 1 failure: test_nodelink_share.py::test_one_call_creates_..._audits — Mac node no longer attached; likely culprit 96e7a8396 (Task 8748, NodeLink off on macOS). Nothing merged; queue empty. Memory: none applied.