swarm: named scheduled prompts for one or more agents, fired in each agent

swarm-controller keeps every scheduled prompt (id, name, agents, body,
anchor, interval, paused) as one document under one key of a new
`schedule-definitions` KV bucket, so each change is a single
compare-and-set and a prompt exists for all of its agents or none. It
writes each agent's key of a new `agent-schedules` bucket as the prompts
naming that agent, without names or other agents, after every change and
on a one-minute reconcile pass. It is the only writer of both, behind
GET/POST /api/schedules and PATCH/DELETE /api/schedules/{id}.
`swarmctl schedule add|list|edit|pause|resume|rm` drives those routes over
the controller socket.

An agent's own queue credential is granted one more subject, the direct
get of its own key in `agent-schedules`. A KV watch is not granted: its
consumer create subject carries no key, so it would cover every agent's.

hive-agent's new schedule ticker reads that key every 10 seconds and fires
due slots as the same `schedule:<id>` todo hive-c0re's worker pushes. Fire
times are anchor + k*interval; the last fired slot per schedule id is kept
in the state db, so a body edit or list refresh never moves or refires a
slot, downtime fires the latest missed slot once, a restart refires
nothing, a one-shot fires once, and paused slots are skipped.

Refs #4914

swarm-queue-client/Cargo.toml

@@ -33,6 +33,10 @@ notices = ["async-nats/jetstream"]
 # `subagent_term::open_or_create`, for swarm-controller, which creates every
 # agent's subagent stream. Explicit for the same reason as `notices`.
 subagent-term = ["async-nats/jetstream"]
+# `agent_schedules::read_own`, for the agent harness, which reads its own
+# schedule key without opening the bucket. Explicit for the same reason as
+# `notices`.
+agent-schedules = ["async-nats/jetstream"]
 
 [dependencies]
 # Bare (no `kv`/`jetstream`) unless a consumer opts into the `kv` feature