Review finding K1 of R4e, issue 1301 S4 (ADR 0503 §3, ADR 0513 §4: the forge
requires mesh/check alone). gitea_check_status rested on "only the bridge
invokes it", but node-tools invokes every tool and a tool is told no caller,
so any session could set mesh/check and merge past the checker.
The bridge now emits check.status on mesh.mod.mesh-delivery-forge-bridge.event.
check.status, which the bus grants to its own account alone (emits), with the
owed status, its key and its revision; the event id check.<key>.<rev> is the
bus's dedup id. A status the bus did not take is not kept as done. OwedAct
refuses mesh/check, and gitea.gitea_check_status leaves the invokes. The
integration test shows the tool runner's account refused on that subject and
gitea's durable consumer handed statuses emitted before it fetched.