hivectl: error on pause/resume of a non-existent agent

hivectl/src/agents.rs

@@ -204,7 +204,19 @@ pub(crate) async fn agents_list(socket: &Path, json: bool) -> Result<()> {
 /// `hivectl agent <name> pause|resume` — flip the agent's pause marker. Not a
 /// DAG, so there's nothing to wait on: the daemon writes the marker and
 /// the harness picks it up on its next poll.
+///
+/// Checks existence first, same as `agents_start` above — the daemon side
+/// (`Coordinator::set_paused`) writes the marker file unconditionally via
+/// the priv-helper and has no notion of "no such agent", so without this
+/// check `hivectl agent typo-name resume` would exit 0 and print
+/// `resumed: typo-name` for a name that was never a real agent.
 async fn set_paused(socket: &Path, name: &str, paused: bool) -> Result<()> {
+    if !crate::util::agent_exists(socket, name).await? {
+        bail!(
+            "no such agent: '{name}' (no state dir under {}/)",
+            hive_host_sock::AGENTS_ROOT
+        );
+    }
     let resp = crate::client::request(
         socket,
         HostRequest::SetPaused {