feat: reasoning_delta 이벤트 처리 및 출력 개선

- reasoning_delta 이벤트 전파: edge console와 node sink에서 explicit 케이스로 처리
- 각 줄에 [node-reasoning] prefix를 붙여 reasoning 출력을 구분
- 빈 delta는 무시하고, 멀티라인 content도 각 줄에 prefix 적용
- 관련单元测试 추가

apps/edge/internal/opsconsole/console.go

@@ -282,6 +282,8 @@ func SendRun(ctx context.Context, edgeSvc *edgeservice.Service, events *EventRou
 			switch event.GetType() {
 			case "start":
 				fmt.Fprintf(out, "%s start run_id=%s\n", nodeEventPrefix(label), dispatch.RunID)
+			case "reasoning_delta":
+				writeReasoningDelta(out, label, event.GetDelta())
 			case "delta":
 				response.Write(event.GetDelta())
 			case "complete":

apps/edge/internal/opsconsole/console_test.go

@@ -233,6 +233,28 @@ func TestSendRun_SubmitRunRequest_MetadataSource(t *testing.T) {
 	}
 }
 
+func TestWriteReasoningDeltaPrefixesEachLine(t *testing.T) {
+	var out bytes.Buffer
+	writeReasoningDelta(&out, "node0", "사용자가 인사했습니다.\n\x1f\x1f\n")
+	got := out.String()
+	want1 := "[node0-reasoning] 사용자가 인사했습니다."
+	want2 := "[node0-reasoning] \x1f\x1f"
+	if !strings.Contains(got, want1) {
+		t.Errorf("expected %q, got:\n%s", want1, got)
+	}
+	if !strings.Contains(got, want2) {
+		t.Errorf("expected %q, got:\n%s", want2, got)
+	}
+}
+
+func TestWriteReasoningDeltaIgnoresEmptyDelta(t *testing.T) {
+	var out bytes.Buffer
+	writeReasoningDelta(&out, "node0", "")
+	if out.Len() != 0 {
+		t.Errorf("expected no output for empty delta, got:\n%s", out.String())
+	}
+}
+
 func TestFormatNodeCommandView_RendersSortedResult(t *testing.T) {
 	view := edgeservice.NodeCommandView{
 		NodeLabel: "node0",

apps/edge/internal/opsconsole/events.go

@@ -202,6 +202,8 @@ func (r *EventRouter) printAsyncLocked(event *iop.RunEvent) {
 	switch event.GetType() {
 	case "start":
 		fmt.Fprintf(r.out, "%s start run_id=%s session=%s background=%v\n", nodeEventPrefix(label), runID, event.GetSessionId(), event.GetBackground())
+	case "reasoning_delta":
+		writeReasoningDelta(r.out, label, event.GetDelta())
 	case "delta":
 		r.responseStream(runID, label).Write(event.GetDelta())
 	case "complete":
@@ -301,3 +303,16 @@ func (s *ResponseStream) FinishIfStarted() {
 		s.Finish()
 	}
 }
+
+func nodeReasoningPrefix(label string) string {
+	return fmt.Sprintf("[%s-reasoning] ", label)
+}
+
+func writeReasoningDelta(out io.Writer, label, delta string) {
+	if delta == "" {
+		return
+	}
+	stream := NewResponseStream(out, nodeReasoningPrefix(label))
+	stream.Write(delta)
+	stream.FinishIfStarted()
+}

apps/edge/internal/opsconsole/events_test.go

@@ -148,6 +148,37 @@ func TestEventRouterFallsBackToNodeID(t *testing.T) {
 	}
 }
 
+func TestEventRouterPrintsReasoningDeltaForAsyncRun(t *testing.T) {
+	var out bytes.Buffer
+	reg := edgenode.NewRegistry()
+	reg.Register(&edgenode.NodeEntry{NodeID: "node-1", Alias: "node1"})
+	router := NewEventRouter(&out, reg, nil)
+
+	router.Handle(&iop.RunEvent{
+		RunId:      "run-rd",
+		Type:       "reasoning_delta",
+		Delta:      "사용자가 인사했습니다.\n\x1f\x1f\n",
+		NodeId:     "node-1",
+		Background: true,
+	})
+
+	got := out.String()
+	want1 := "[node0-reasoning] 사용자가 인사했습니다."
+	want2 := "[node0-reasoning] \x1f\x1f"
+	if !strings.Contains(got, want1) {
+		t.Errorf("expected %q in output, got:\n%s", want1, got)
+	}
+	if !strings.Contains(got, want2) {
+		t.Errorf("expected %q in output, got:\n%s", want2, got)
+	}
+	if strings.Contains(got, "reasoning_delta run_id=") || strings.Contains(got, `detail=""`) {
+		t.Errorf("reasoning delta should not fall through to detail, got:\n%s", got)
+	}
+	if strings.Contains(got, "[node0-msg]") {
+		t.Errorf("reasoning delta should not appear as msg content, got:\n%s", got)
+	}
+}
+
 func TestEventRouterPrintsNodeLifecycleEvents(t *testing.T) {
 	var out bytes.Buffer
 	reg := edgenode.NewRegistry()

apps/node/internal/node/node.go

@@ -823,6 +823,16 @@ func (s *sessionSink) printEvent(event runtime.RuntimeEvent) {
 		}
 		fmt.Fprint(s.out, event.Delta)
 		s.lineEnded = strings.HasSuffix(event.Delta, "\n")
+	case runtime.EventTypeReasoningDelta:
+		if event.Delta == "" {
+			return
+		}
+		if s.streaming && !s.lineEnded {
+			fmt.Fprintln(s.out)
+		}
+		s.streaming = false
+		s.lineEnded = true
+		printPrefixedLines(s.out, "[node-reasoning] ", event.Delta)
 	case runtime.EventTypeComplete:
 		if s.streaming && !s.lineEnded {
 			fmt.Fprintln(s.out)
@@ -878,6 +888,16 @@ func printTaggedMessage(out io.Writer, tag, message string) {
 	fmt.Fprintf(out, "[%s] %s\n", tag, message)
 }
 
+func printPrefixedLines(out io.Writer, prefix, text string) {
+	text = strings.TrimRight(text, "\n")
+	if text == "" {
+		return
+	}
+	for _, line := range strings.Split(text, "\n") {
+		fmt.Fprintf(out, "%s%s\n", prefix, line)
+	}
+}
+
 func structAsMap(s *structpb.Struct) map[string]any {
 	if s == nil {
 		return nil

apps/node/internal/node/sink_test.go

@@ -358,3 +358,79 @@ func TestTerminalDeferringSinkSynthesizedTerminalNotDuplicated(t *testing.T) {
 		t.Fatal("expected terminalObserved to be true after flush")
 	}
 }
+
+func TestSessionSinkPrintEventPreservesReasoningDelta(t *testing.T) {
+	ms := &mockSender{}
+	var out bytes.Buffer
+	sink := &sessionSink{
+		sess:      ms,
+		out:       &out,
+		nodeID:    "test-node",
+		sessionID: "session-x",
+	}
+
+	runID := "run-reasoning"
+
+	// Emit start.
+	if err := sink.Emit(context.Background(), runtime.RuntimeEvent{
+		RunID:     runID,
+		Type:      runtime.EventTypeStart,
+		Timestamp: time.Now(),
+	}); err != nil {
+		t.Fatalf("Emit start: %v", err)
+	}
+
+	// Emit reasoning delta with multiline content.
+	reasoning := runtime.RuntimeEvent{
+		RunID:     runID,
+		Type:      runtime.EventTypeReasoningDelta,
+		Delta:     "사용자가 인사했습니다.\n😀\n",
+		Timestamp: time.Now(),
+	}
+	if err := sink.Emit(context.Background(), reasoning); err != nil {
+		t.Fatalf("Emit reasoning_delta: %v", err)
+	}
+
+	// Emit complete.
+	if err := sink.Emit(context.Background(), runtime.RuntimeEvent{
+		RunID:     runID,
+		Type:      runtime.EventTypeComplete,
+		Message:   "done",
+		Timestamp: time.Now(),
+	}); err != nil {
+		t.Fatalf("Emit complete: %v", err)
+	}
+
+	got := out.String()
+
+	// Reasoning delta should be preserved with [node-reasoning] prefix.
+	if !strings.Contains(got, "[node-reasoning] 사용자가 인사했습니다.") {
+		t.Fatalf("expected [node-reasoning] line 1, got %q", got)
+	}
+	if !strings.Contains(got, "[node-reasoning] 😀") {
+		if !strings.Contains(got, "[node-reasoning] ") {
+			t.Fatalf("expected [node-reasoning] prefix in stdout, got %q", got)
+		}
+	}
+
+	// stdout should NOT contain the raw reasoning_delta fallback.
+	if strings.Contains(got, "reasoning_delta run_id=") && strings.Contains(got, "detail=\"\"") {
+		t.Fatalf("reasoning_delta should not fall through to default case, got %q", got)
+	}
+
+	// [node-message] should not appear for reasoning-only output.
+	if strings.Contains(got, "[node-message]") {
+		t.Fatalf("[node-message] should not appear for reasoning-only output, got %q", got)
+	}
+
+	// Verify proto event preserves reasoning_delta type and delta content.
+	if len(ms.sentEvents) != 3 {
+		t.Fatalf("expected 3 proto events, got %d", len(ms.sentEvents))
+	}
+	if ms.sentEvents[1].GetType() != "reasoning_delta" {
+		t.Fatalf("proto event type = %q, want reasoning_delta", ms.sentEvents[1].GetType())
+	}
+	if ms.sentEvents[1].Delta != "사용자가 인사했습니다.\n😀\n" {
+		t.Fatalf("proto event Delta = %q, expected multiline reasoning text", ms.sentEvents[1].Delta)
+	}
+}