Merge lane base check: develop 3f7241bff0b2

Merge lane base check: run the full gate on `develop` at `3f7241bff0b2823f847dd272eac7881db28ca08f` 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 3f7241bff0b2 is red: 3 mirror stages fail on lifecycle.py:96 citing docs/policies/repo-access-levels.md, which the CE tree lacks (from 2eb314ce9d). Lane reported develop_red, fix task #11000 filed. Memory: none applied.