hive-c0re/hivectl/hive-agent: pause as a job-queue DAG node (closes #3056)

hive-agent/src/main.rs

@@ -317,6 +317,12 @@ trait Surface {
     /// its timeout fallback.
     fn graceful_stop_complete(socket: &Path) -> impl Future<Output = ()>;
 
+    /// Tell c0re the harness's own pause-marker check (between turns) just
+    /// saw the marker appear (fire-and-forget; logs on error). Lets the
+    /// pause DAG's drain node resolve without waiting out its timeout
+    /// fallback. Same shape as `graceful_stop_complete`.
+    fn pause_acknowledged(socket: &Path) -> impl Future<Output = ()>;
+
     /// Send a message addressed to `<parent>` (broker resolves the
     /// sentinel via `topology::parent_of` at delivery time; root
     /// agents/manager fall through to operator).
@@ -368,6 +374,10 @@ impl Surface for AgentSurface {
         .await;
     }
 
+    async fn pause_acknowledged(socket: &Path) {
+        fire_and_forget(socket, Request::PauseAcknowledged, "pause_acknowledged").await;
+    }
+
     async fn inbox_unread(socket: &Path) -> u64 {
         match hive_sock_client::request::<_, Response>(
             socket,
@@ -700,6 +710,12 @@ async fn serve_loop<S: Surface>(
                     text: "paused: turn loop parked, messages will queue".into(),
                 });
                 was_paused = true;
+                // Fire-and-forget: this is the same "no turn in flight"
+                // moment `GracefulStopComplete` reports at, and needs no
+                // extra tracking for the same reason — the check above is
+                // already between-turns only. Lets the pause DAG's drain
+                // node resolve immediately instead of timing out.
+                S::pause_acknowledged(socket).await;
             }
             tokio::time::sleep(PAUSE_POLL).await;
             continue;