Merge lane base check: develop afea52ee75f1

Merge lane base check: run the full gate on `develop` at `afea52ee75f1f27318578db4558347e7d959c7b8` 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 afea52ee75f1: RED — full gate 54796 passed, 3 API unit tests failed, reconfirmed by a focused rerun; lane reported develop_red (tree 91d3f43a3f), the CP files the fix task. Nothing merged. Memory: none applied.