dual check v0.1

server/internal/tools/dual_check/business_error.go

@@ -0,0 +1,15 @@
+package dual_check
+
+// BusinessError 业务错误
+type BusinessError struct {
+	Code    int
+	Message string
+}
+
+// Error 返回错误描述：优先用自定义 Message，否则回退到 ErrMessage(code)
+func (e *BusinessError) Error() string {
+	if e.Message != "" {
+		return e.Message
+	}
+	return ErrMessage(e.Code)
+}