fix(inventoryTable): 优化折扣合计计算逻辑，使用动态字段countKey替代固定字段totalCount

src/BIZComponents/inventoryTable.vue

@@ -1969,7 +1969,7 @@ export default {
     //获取折让合计
     getDiscountTotalPrice(row) {
       let num = 0;
-      num = Number(row.discountSinglePrice) * Number(row.totalCount);
+      num = Number(row.discountSinglePrice) * Number(row[this.countObj.countKey]);
       return isNaN(num) ? '' : num.toFixed(2);
     },
     orderNoChange(row, item) {