Merge lane base check: develop b99c7552f98b

Merge lane base check: run the full gate on `develop` at `b99c7552f98b435b8e6c01113aa2e0a0657401ff` 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 b99c7552f98b red (develop_red reported, 5 failures, 2× gate): Task refs in mirrored comments (persona_registry.py:458 Task 11245, node_bootstrap.py:405 Task 11248) and postinst sets the credential helper before resolving jaah_home (Task 11239). Memory: none applied.