feat: add set_status MCP tool and status field to whoami/dashboard (closes #325)

hive-c0re/src/agent_server.rs

@@ -220,11 +220,39 @@ async fn dispatch(req: &AgentRequest, agent: &str, coord: &Arc<Coordinator>) ->
                 },
             }
         }
-        AgentRequest::Whoami => AgentResponse::Whoami {
-            name: agent.to_owned(),
-            role: "agent".to_owned(),
-            hyperhive_rev: crate::auto_update::current_flake_rev(&coord.hyperhive_flake),
-        },
+        AgentRequest::Whoami => {
+            let status_text = crate::container_view::read_agent_status_text(agent);
+            AgentResponse::Whoami {
+                name: agent.to_owned(),
+                role: "agent".to_owned(),
+                hyperhive_rev: crate::auto_update::current_flake_rev(&coord.hyperhive_flake),
+                status_text,
+            }
+        }
+        AgentRequest::SetStatus { text } => {
+            let path = crate::coordinator::Coordinator::agent_notes_dir(agent)
+                .join("hyperhive-status");
+            let result = if text.trim().is_empty() {
+                // Empty = clear: remove the file (ignore missing).
+                std::fs::remove_file(&path)
+                    .or_else(|e| if e.kind() == std::io::ErrorKind::NotFound {
+                        Ok(())
+                    } else {
+                        Err(e)
+                    })
+            } else {
+                std::fs::write(&path, format!("{}\n", text.trim()))
+            };
+            match result {
+                Ok(()) => {
+                    // Kick a container rescan so the dashboard updates live.
+                    let coord2 = Arc::clone(coord);
+                    tokio::spawn(async move { coord2.rescan_containers_and_emit().await });
+                    AgentResponse::Ok
+                }
+                Err(e) => AgentResponse::Err { message: format!("set_status write failed: {e}") },
+            }
+        }
         AgentRequest::CancelLooseEnd { kind, id } => crate::questions::handle_cancel_loose_end(
             coord, agent, *kind, *id,
         )