swarm: subagent-status KV bucket, the run state of each subagent

One key per subagent (<agent>.<subagent>) holding running/finished, since,
exit, model, effort and the publish time. The controller creates the bucket,
and the agent credential may publish its own keys. Nothing reads or writes
it yet; the daemon publisher and the controller list follow.

swarm-wire/src/lib.rs

@@ -29,6 +29,7 @@ pub mod router_api;
 pub mod router_sink;
 pub mod router_todo;
 pub mod stt;
+pub mod subagent_status;
 pub mod subagent_term;
 pub mod wanted;