feat(MercProjectGoods): 添加特价活动相关字段

src/main/java/com/xynet/marketing/entity/MercProjectGoods.java

@@ -54,4 +54,14 @@ public class MercProjectGoods implements Serializable {
      * 商品封面
      */
     private String cover;
+
+    /**
+     * 总数量（特价活动专属）
+     */
+    private Integer totalNum;
+
+    /**
+     * 已购买量（特价活动专属）
+     */
+    private Integer buyNum;
 }