Merge lane base check: develop e30e5fbbcab2

Merge lane base check: run the full gate on `develop` at `e30e5fbbcab251e6662427ddc586675b89c55dcc` 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 e30e5fbbcab2: develop_red, reported by merge_lane.py run (2 full-gate runs agree). Red: test_cloud_boot_watch reboot-loop fixture .log is gitignored, never committed (PR #6655); Nodes.filters bulk-Delete vitest. Nothing merged. Memory: none applied.