Merge lane base check: develop dd674ccd7371

Merge lane base check: run the full gate on `develop` at `dd674ccd737106688e7915698be7ea70427a0c5c` 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 dd674ccd7 red: tests/test_virtual_nodes.py::test_a_regular_nodes_bootstrap_is_byte_identical_to_before_hosts_existed fails, and again when rerun alone (likely Task 11113's bootstrap change). develop_red reported; no PRs ejected. Memory: none applied