Merge lane base check: develop 5105677f6c49

Merge lane base check: run the full gate on `develop` at `5105677f6c498a36aa50b1d95721bc3bb9c1aaf2` 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.

Base check develop 5105677f6c49: develop_red (full gate, 3 failed): vitest muted-text Typography palette-colour test; tests/test_api_keys.py::test_act_as_cannot_strip_a_key_s_attribution. Lane reported it; queue empty. Memory: none applied.