Merge lane base check: develop 170a97295af3

Merge lane base check: run the full gate on `develop` at `170a97295af3045f4742e0687a19ef033fe3b08f` 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 170a97295af3 is RED; develop_red reported. 1 e2e failure, repeated when run alone: tenant-isolation.spec.ts:244 (/settings row is hidden, likely from 021963d0c). 56,795 passed. Nothing queued, nothing merged, nothing ejected. Memory: none applied.