Merge lane base check: develop 091ccafcab19

Merge lane base check: run the full gate on `develop` at `091ccafcab1904521023d616aac9f71d943265c9` 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 091ccafcab19 red (develop_red reported): Markdown links — jaah-ai/jaah-ce link 404 in apps/docs/content/faq/editions-and-source.md (also a flaky gate-result selftest on 1st run). Fix task #11141 filed. Memory: none applied.