feat(pricing): 添加折扣优先级设置并优化价格计算请求

- 在折扣信息中增加优先级字段，提升折扣策略的灵活性
- 为价格计算请求默认启用自动使用优惠券功能
- 设置价格预览模式为非预览状态，确保实际计算准确性
- 完善打印服务中的价格计算逻辑，提高系统稳定性

src/main/java/com/ycwl/basic/pricing/service/impl/OnePricePurchaseDiscountProvider.java

@@ -83,6 +83,7 @@ public class OnePricePurchaseDiscountProvider implements IDiscountProvider {
             discountInfo.setDiscountAmount(onePriceInfo.getActualDiscountAmount());
             discountInfo.setDiscountDescription("景区一口价购买，价格更优惠");
             discountInfo.setOnePriceInfo(onePriceInfo);
+            discountInfo.setPriority(getPriority());
             
             discounts.add(discountInfo);
             

src/main/java/com/ycwl/basic/service/printer/impl/PrinterServiceImpl.java

@@ -454,6 +454,7 @@ public class PrinterServiceImpl implements PrinterService {
                         memberId, faceId, scenicId, e.getMessage());
             }
         }
+        request.setAutoUseCoupon(true);
 
         // 使用统一价格计算服务
         PriceCalculationResult result = priceCalculationService.calculatePrice(request);
@@ -669,6 +670,8 @@ public class PrinterServiceImpl implements PrinterService {
         }
 
         request.setProducts(productItems);
+        request.setAutoUseCoupon(true);
+        request.setPreviewOnly(false);
 
         PriceCalculationResult priceResult = priceCalculationService.calculatePrice(request);