swarm-controller now creates `term-sub-<agent>` for every agent a hive is
declared to run, at start and every minute after, with the config
`swarm_queue_client::subagent_term::open_or_create` spells (subjects
`$SWARM.term.<agent>.sub.>`, max_age 24h). An existing stream is opened as
it is, as the controller does for its other streams and buckets, under the
`$JS.API.STREAM.CREATE.*` grant it already holds.
The agent no longer creates the stream: its token is granted publish on
`$SWARM.term.<agent>.sub.>` and no `$JS.API.STREAM.CREATE|INFO` subject,
and the subagent daemon only publishes. A `CREATE` carries the stream's
config in its payload, which no subject grant narrows, so the agent could
otherwise pick the stream's subjects and limits.
318f67cda9