fix(ticket): 优化库存和限购数量显示逻辑

- 使用 hasValue 方法统一判断数值是否有效
- 避免显示无意义的 0 或空值
- 添加 hasValue 工具函数注释说明
- 修正上架按钮点击事件参数传递问题

src/views/ticketManagement/couponDetail.vue

@@ -89,7 +89,7 @@
           <div class="detail-item" v-if="couponModel.hasMinimumSpend === 1">
             <div class="detail-label">最低消费金额</div>
             <div class="detail-value">
-              {{ couponModel.minimumSpendingAmount ? `¥${couponModel.minimumSpendingAmount}` : "--" }}
+              {{ formatCurrency(couponModel.minimumSpendingAmount, 2, "￥") }}
             </div>
           </div>
           <!-- 补充说明 -->

src/views/ticketManagement/newCoupon.vue

@@ -175,6 +175,10 @@ const rules = reactive({
   minimumSpendingAmount: [
     { required: true, message: "请输入最低消费金额" },
     {
+      validator: validatePositiveNumber("最低消费金额必须为正数"),
+      trigger: "blur"
+    },
+    {
       validator: validatePriceFormat("整数部分最多6位，小数部分最多2位"),
       trigger: "blur"
     }