The header on `$SWARM.agent-state.<agent>` went out only when a bus event
changed it, and the core subject keeps nothing for a late subscriber. An
idle agent therefore said nothing to a reader that attached after its
last change: swarm-controller after a restart showed `effective: null`
for that agent until its next turn, which can be hours.
The publish loop now also wakes every 60 s and re-sends the current
header through the same `publish` path (clearing the dedup state first).
Transitions still go out as they happen. Same subject, same grant.
An agent whose queue connection is down now logs `swarm agent state:
publish skipped` once a minute even while idle, so the
`hh-swarm-agent-state-publish-skipped` alert also fires for idle
disconnected agents, not only busy ones.
Refs #5034
19a045a401