The swarm controller offers its own running rev (services.hyperhive.c0re.
hyperhiveRev) as the hyperhive pin of internal/meta and takes it only when
the forge compare API shows it descends from the committed pin; merges to
hyperhive main no longer move the pin, and the first commit pins main's head.
When a commit moves the pin, every placed agent gets a TriggerDeploy.
A deploy after a meta update no longer waits on it succeeding (after_any), so
a down builder does not hold back hives that render locally.