feat: expand node agent routing and media artifacts

pkg/agent/loop.go

@@ -352,10 +352,15 @@ func (al *AgentLoop) dispatchNodeSubagentTask(ctx context.Context, task *tools.S
 		return "", fmt.Errorf("node-backed subagent %q missing node_id", task.AgentID)
 	}
 	taskInput := loopTaskInputForNode(task)
+	reqArgs := map[string]interface{}{}
+	if remoteAgentID := remoteAgentIDForNodeBranch(task.AgentID, nodeID); remoteAgentID != "" {
+		reqArgs["remote_agent_id"] = remoteAgentID
+	}
 	resp, err := al.nodeRouter.Dispatch(ctx, nodes.Request{
 		Action: "agent_task",
 		Node:   nodeID,
 		Task:   taskInput,
+		Args:   reqArgs,
 	}, "auto")
 	if err != nil {
 		return "", err
@@ -372,6 +377,23 @@ func (al *AgentLoop) dispatchNodeSubagentTask(ctx context.Context, task *tools.S
 	return fmt.Sprintf("node %s completed agent_task", nodeID), nil
 }
 
+func remoteAgentIDForNodeBranch(agentID, nodeID string) string {
+	agentID = strings.TrimSpace(agentID)
+	nodeID = strings.TrimSpace(nodeID)
+	if agentID == "" || nodeID == "" {
+		return ""
+	}
+	prefix := "node." + nodeID + "."
+	if !strings.HasPrefix(agentID, prefix) {
+		return ""
+	}
+	remote := strings.TrimPrefix(agentID, prefix)
+	if strings.TrimSpace(remote) == "" {
+		return ""
+	}
+	return remote
+}
+
 func loopTaskInputForNode(task *tools.SubagentTask) string {
 	if task == nil {
 		return ""

pkg/agent/subagent_node_test.go

@@ -23,6 +23,9 @@ func TestDispatchNodeSubagentTaskUsesNodeAgentTask(t *testing.T) {
 		if req.Action != "agent_task" {
 			t.Fatalf("unexpected action: %s", req.Action)
 		}
+		if got, _ := req.Args["remote_agent_id"].(string); got != "coder" {
+			t.Fatalf("expected remote_agent_id=coder, got %+v", req.Args)
+		}
 		if !strings.Contains(req.Task, "Parent Agent: main") {
 			t.Fatalf("expected parent-agent context in task, got %q", req.Task)
 		}
@@ -43,7 +46,7 @@ func TestDispatchNodeSubagentTaskUsesNodeAgentTask(t *testing.T) {
 	}
 	out, err := loop.dispatchNodeSubagentTask(context.Background(), &tools.SubagentTask{
 		ID:            "subagent-1",
-		AgentID:       "node.edge-dev.main",
+		AgentID:       "node.edge-dev.coder",
 		Transport:     "node",
 		NodeID:        "edge-dev",
 		ParentAgentID: "main",