Optionalliveness_probe: BerthLivenessProbe
Optional reachability probe; when present, dead berths are reaped and never returned.
Lists every live berth (for a bare --remote with several daemons).
The live berths, dead ones reaped.
Resolves one identity to a live berth.
A normalised identity from identity_normalise.
The live berth, or null when none is advertised or it is dead.
The tier-1 resolver: reads identity-keyed berth files and, when given a liveness probe, reaps any berth whose daemon has gone (passive cleanup — the next read of a stale berth removes it). Without a probe it returns berths as recorded, trusting the caller's own attach to surface a dead one.