Merge lane base check: develop 0d1e4d92ae33

Merge lane base check: run the full gate on `develop` at `0d1e4d92ae33375cadc4ade102db81070f23f306` 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 0d1e4d92ae33 certified: full gate green on attempt 2. Attempt 1 failed 1 flaky vitest test (Tasks.rowActions "merged-PR link on confirmed done task", empty render under load). Nothing ejected. Memory: none applied.