Merge lane base check: develop 10cc641b3867

Merge lane base check: run the full gate on `develop` at `10cc641b38672d36a48c7621d5ad7a2c86650426` 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 10cc641b3867 is red: the full gate failed 2× with the same 4 stages (quarantine lane selftest, mirror trees strict, community edition tooling, mirror sensitive-content). The lane reported develop_red. Memory: none applied.