Once main requires mesh/check, nothing writes mesh/merge-gate, and the merge
tool, which judged on it, would refuse every merge. It now judges on the
status the base requires: mesh/check's line names the trunk it judged, an
out-of-date one is refused and nothing is asked (the checker re-checks on a
trunk move, ADR 0447 §4); hq's mesh/repo-check is judged as before. The
announcer, the verdict, a trunk's move and a build's start write the
controller's two statuses only where a base still requires them, so hq keeps
mesh/repo-check and no stale mesh/merge-gate appears anywhere else.
The controller now decides what a pull request's check runs from the mesh's module
graph, so the announcement carries the changed directories that hold a module at the
head and whether the head has a merge-check.sh. A verdict sets mesh/merge-gate (the
gate, with the modules it judged) and mesh/repo-check (the repository's own tests).
gitea_branch_protection_get/set let the operator's agent make those statuses required.
The catalogue's merge-check.sh leaves the gate to the build seat and keeps its own layer:
every manifest through module check, and the touched Go modules' tests.