Deckies merged in from a prior deployment's saved state kept their
original host_uuid — which dispatch_decnet_config then 404'd on if that
host had since been decommissioned or re-enrolled at a different uuid.
Before round-robin assignment, drop any host_uuid that isn't in the live
swarm_hosts set so orphaned entries get reassigned instead of exploding
with 'unknown host_uuid'.
anti
6d7567b6bb