Merge lane base check: develop 803f7958bc99

Merge lane base check: run the full gate on `develop` at `803f7958bc99393eba9990deb350dca00b9454a7` 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 803f7958bc99: develop_red (recorded by merge_lane.py run). 4 API unit tests fail and fail again alone: _wt_out destroy_node_error TypeError ×2 and a pool-slots authz 403 (both Task 9011), plus wait_cloud_node_power missing from workflow_registry. Queue empty, nothing ejected. Memory: none applied.