phase 8 step 2: approval-gated spawn + dashboard spinner

hive-c0re/src/coordinator.rs

@@ -30,6 +30,24 @@ pub struct Coordinator {
     /// `flake.nix` files as `inputs.hyperhive.url`.
     pub hyperhive_flake: String,
     agents: Mutex<HashMap<String, AgentSocket>>,
+    /// Agents whose lifecycle action (currently just spawn) is in flight.
+    /// Read by the dashboard to render a spinner; cleared when the action
+    /// resolves (success or failure).
+    transient: Mutex<HashMap<String, TransientState>>,
+}
+
+/// Per-agent in-progress state that the dashboard surfaces between approve
+/// click and container ready.
+#[derive(Debug, Clone)]
+pub struct TransientState {
+    pub kind: TransientKind,
+    pub since: std::time::Instant,
+}
+
+#[derive(Debug, Clone, Copy)]
+pub enum TransientKind {
+    /// `lifecycle::spawn` is running (nixos-container create + update + start).
+    Spawning,
 }
 
 impl Coordinator {
@@ -41,6 +59,7 @@ impl Coordinator {
             approvals: Arc::new(approvals),
             hyperhive_flake,
             agents: Mutex::new(HashMap::new()),
+            transient: Mutex::new(HashMap::new()),
         })
     }
 
@@ -64,6 +83,25 @@ impl Coordinator {
         }
     }
 
+    /// Mark an agent as in-progress (only one state per agent for now).
+    pub fn set_transient(&self, name: &str, kind: TransientKind) {
+        self.transient.lock().unwrap().insert(
+            name.to_owned(),
+            TransientState {
+                kind,
+                since: std::time::Instant::now(),
+            },
+        );
+    }
+
+    pub fn clear_transient(&self, name: &str) {
+        self.transient.lock().unwrap().remove(name);
+    }
+
+    pub fn transient_snapshot(&self) -> HashMap<String, TransientState> {
+        self.transient.lock().unwrap().clone()
+    }
+
     pub fn agent_dir(name: &str) -> PathBuf {
         PathBuf::from(format!("{AGENT_RUNTIME_ROOT}/{name}"))
     }