fix(#64): bound purchase spec selection retries

server/app/goauto/purchase/lifecycle.go

@@ -268,11 +268,22 @@ func (s *Service) SubmitResult(ctx context.Context, taskID uint64, req ResultReq
 			if len(req.ProbedSpecs) == 0 {
 				return TaskPayload{}, fail(CodeInvalidRequest, "规格探测结果无效")
 			}
-			next = models.PurchaseTaskStatusSpecProbePending
-			a.Status = models.PurchaseAttemptStatusCompleted
-			t.SpecSource = "unresolved"
-			t.MappedColorSnapshot = ""
-			t.MappedSizeSnapshot = ""
+			if t.SpecDecisionRequestID != nil {
+				// One slow-path decision has already been frozen for this task. A
+				// second probe means the Agent still could not select that exact
+				// decision. Fail closed instead of clearing the auditable decision
+				// and leaving an active task that can be dispatched forever.
+				next = models.PurchaseTaskStatusFailed
+				a.Status = models.PurchaseAttemptStatusFailed
+				code, message := "PURCHASE_SPEC_NOT_MATCHED", "再次执行仍未能精确选择商品规格，请检查商品规格"
+				t.ErrorCode, t.ErrorMessage = &code, &message
+			} else {
+				next = models.PurchaseTaskStatusSpecProbePending
+				a.Status = models.PurchaseAttemptStatusCompleted
+				t.SpecSource = "unresolved"
+				t.MappedColorSnapshot = ""
+				t.MappedSizeSnapshot = ""
+			}
 		case "rehearsal_completed":
 			if t.ExecutionMode != models.PurchaseExecutionModeRehearsal {
 				return TaskPayload{}, fail(CodeStateConflict, "正式任务不能提交演练结果")
@@ -322,7 +333,7 @@ func (s *Service) SubmitResult(ctx context.Context, taskID uint64, req ResultReq
 		}
 		return valuePayload(s, t, a, false)
 	})
-	if err != nil || req.ResultType != "spec_probe_completed" || payload.Replayed {
+	if err != nil || req.ResultType != "spec_probe_completed" || payload.Replayed || payload.Status != models.PurchaseTaskStatusSpecProbePending {
 		return payload, err
 	}
 	return s.resolveProbedSpecs(ctx, taskID, req.TaskAttemptID, req.ProbedSpecs)

server/app/goauto/purchase/service_test.go

@@ -230,6 +230,48 @@ func TestSlowPathUsesTwoAttemptsAndFreezesDecision(t *testing.T) {
 	}
 }
 
+func TestSecondSpecProbeFailsClosedWithoutClearingDecision(t *testing.T) {
+	db := testDB(t)
+	f := seed(t, db, liveCaps(), false)
+	s := testService(db)
+	task, err := createLive(t, s, f)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err = s.Claim(context.Background(), task.ID, ActionRequest{RequestID: uuid.NewString()}, f.token); err != nil {
+		t.Fatal(err)
+	}
+	first, err := s.Start(context.Background(), task.ID, ActionRequest{RequestID: uuid.NewString()}, f.token)
+	if err != nil {
+		t.Fatal(err)
+	}
+	probe := json.RawMessage(`{"dimensions":[{"key":"color","values":["黑色"]},{"key":"size","values":["XL"]}]}`)
+	if _, err = s.SubmitResult(context.Background(), task.ID, ResultRequest{RequestID: uuid.NewString(), TaskAttemptID: first.TaskAttemptID, ResultType: "spec_probe_completed", ProbedSpecs: probe}, f.token); err != nil {
+		t.Fatal(err)
+	}
+	if _, err = s.Claim(context.Background(), task.ID, ActionRequest{RequestID: uuid.NewString()}, f.token); err != nil {
+		t.Fatal(err)
+	}
+	second, err := s.Start(context.Background(), task.ID, ActionRequest{RequestID: uuid.NewString()}, f.token)
+	if err != nil || second.Phase != models.PurchaseAttemptPhasePurchase {
+		t.Fatalf("second attempt: %+v %v", second, err)
+	}
+	result, err := s.SubmitResult(context.Background(), task.ID, ResultRequest{RequestID: uuid.NewString(), TaskAttemptID: second.TaskAttemptID, ResultType: "spec_probe_completed", ProbedSpecs: probe}, f.token)
+	if err != nil || result.Status != models.PurchaseTaskStatusFailed {
+		t.Fatalf("second probe must fail closed: %+v %v", result, err)
+	}
+	var saved models.PurchaseTask
+	if err = db.First(&saved, task.ID).Error; err != nil {
+		t.Fatal(err)
+	}
+	if saved.ErrorCode == nil || *saved.ErrorCode != "PURCHASE_SPEC_NOT_MATCHED" {
+		t.Fatalf("unexpected failure: %v %v", saved.ErrorCode, saved.ErrorMessage)
+	}
+	if saved.MappedColorSnapshot != "黑色" || saved.MappedSizeSnapshot != "XL" || saved.SpecDecisionRequestID == nil {
+		t.Fatalf("the first decision must remain auditable: %+v", saved)
+	}
+}
+
 func TestCreateUsesDeterministicTraditionalAndWeightMatching(t *testing.T) {
 	db := testDB(t)
 	f := seed(t, db, liveCaps(), false)