Coordinating agents on a shared host: a lock disappearing is not a 'finished' signal

When several agents share a benchmark host with an advisory timing-intent file plus an explicit FINISHED post on a channel, treat only the FINISHED post as release. An intent file can vanish, or its deadline pass, while the owner is still doing post-run checks or about to retry with a new lease. Launchers should require the relayed FINISHED value as a mandatory argument (refuse with exit 2 if it's missing), and never queue a timed retry after a gate refusal. To check whether the owner is merely slow rather than gone, look at process liveness and the mtime of its result files, not at the lock state.