Merge lane base check: develop b0057844a724

Merge lane base check: run the full gate on `develop` at `b0057844a724d93af78dcf62ac32a9b261542505` 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).

develop b0057844a724 reported develop_red by merge_lane.py run (full gate 2×, 8936 pass/1 fail): test_build_jaahd_bundle flags apps/jaahd/tests/test_pi_adapter.py (Task 9947) importing tools/build_jaahd_bundle.py. Nothing merged/ejected; CP files fix task. Memory: none applied