hivectl: add start/stop agent verbs, rename spawn to create

CLAUDE.md

@@ -39,9 +39,10 @@ hand-maintained per-file tree drifts out of sync with the code.
 - **`hivectl/`** — standalone operator CLI (`hivectl` binary). Talks to
   the `hive-c0re` daemon over the host admin socket (`hive-host-sock`
   wire types) — does NOT link `hive-c0re`. Verbs: `list-agents`,
-  `agent <name> <spawn|kill|destroy|rebuild|restart|set-parent|choom|
-  watch|…>`, `approvals <pending|approve|deny>`, `forge`/`matrix`/
-  `github`/`gateway` provisioning, `stop`/`start`, `wg`/`peer-config`.
+  `agent <name> <start|create|request-create|stop|kill|destroy|rebuild|
+  restart|set-parent|choom|watch|…>`, `approvals <pending|approve|deny>`,
+  `forge`/`matrix`/`github`/`gateway` provisioning, `stop`/`start`,
+  `wg`/`peer-config`.
 - **`hive-agent/`**, **`hive-agent-mcp/`** —
   in-container harness, two sibling crates for every agent (not a
   single `hive-ag3nt/` dir — that's the runtime/binary-family nickname,