feat: enqueue graph join after fan-in

modules/work/application/graph_runtime.go

@@ -106,6 +106,12 @@ func CompleteGraphNode(ctx context.Context, store ports.GraphStore, graphID stri
 			for _, candidate := range ready {
 				if graph.Nodes[i].ID == candidate && graph.Nodes[i].State == work.GraphNodeBlocked {
 					graph.Nodes[i].State = work.GraphNodeReady
+					if graph.Nodes[i].DispatchID == "" {
+						return work.WorkGraph{}, ErrGraphDispatchBinding
+					}
+					if err := store.EnqueueDispatch(ctx, work.AgentDispatchQueueItem{DispatchID: graph.Nodes[i].DispatchID, State: work.AgentDispatchQueued, AvailableAtUnixMillis: time.Now().UnixMilli(), UpdatedAtUnixMillis: time.Now().UnixMilli()}); err != nil {
+						return work.WorkGraph{}, err
+					}
 				}
 			}
 		}

tests/agent_execution/graph_runtime_test.go

@@ -50,6 +50,9 @@ func TestGraphRuntimeSchedulesFanOutAndCompletesFanIn(t *testing.T) {
 	if _, err := application.CompleteGraphNode(context.Background(), store, "g", 3, "b", true); err != nil {
 		t.Fatal(err)
 	}
+	if len(store.queued) != 3 || store.queued[2] != "d-join" {
+		t.Fatalf("fan-in dispatch was not enqueued: %v", store.queued)
+	}
 	completed, err := application.CompleteGraphNode(context.Background(), store, "g", 4, "join", true)
 	if err != nil || completed.State != work.GraphCompleted {
 		t.Fatalf("completed=%+v err=%v", completed, err)