fix(backend): ProductSku/ProductSkuDTO 价格字段 BigDecimal(元)→Integer(分)，统一价格单位

cfc-backend/src/main/java/com/etotem/cfc/dto/ProductSkuDTO.java

@@ -4,7 +4,6 @@ import com.alibaba.fastjson.JSON;
 import com.alibaba.fastjson.TypeReference;
 import com.etotem.cfc.entity.ProductSku;
 import lombok.Data;
-import java.math.BigDecimal;
 import java.util.Map;
 
 @Data
@@ -13,8 +12,8 @@ public class ProductSkuDTO {
     private Long productId;
     private String skuCode;
     private Map<String, String> specs;
-    private BigDecimal price;
-    private BigDecimal originalPrice;
+    private Integer price;
+    private Integer originalPrice;
     private Integer stock;
     private String image;
     private Boolean enabled;

cfc-backend/src/main/java/com/etotem/cfc/entity/ProductSku.java

@@ -18,12 +18,12 @@ public class ProductSku implements Serializable {
     private Long productId;
     private String skuCode;
     private String specs;
-    private BigDecimal price;
+    private Integer price;
     private BigDecimal purchasePrice; // 进价(分)
     private Integer stock;
     private Integer minStockAlert;
     private Integer minQuantity; // 最小购买数量限制
-    private BigDecimal originalPrice;
+    private Integer originalPrice;
     private String image;
     private Integer enabled;
     private Date createTime;

cfc-backend/src/main/java/com/etotem/cfc/service/ProductOrderService.java

@@ -461,7 +461,7 @@ public class ProductOrderService {
                         return Result.error(product.getName() + " 该规格最低需购买" + sku.getMinQuantity() + "件");
                     }
                     if (sku.getPrice() != null) {
-                        unitPrice = sku.getPrice().multiply(new java.math.BigDecimal(100)).intValue();
+                        unitPrice = sku.getPrice();
                     }
                 }
             }