fix(ticketManagement): 修复单日可用数量和限购数量显示逻辑

- 优化单日可用数量的空值判断逻辑
- 优化限购数量的空值判断逻辑
- 避免在数量为0时显示默认值"--"

src/views/ticketManagement/detail.vue

@@ -89,14 +89,14 @@
           <div class="detail-item">
             <div class="detail-label">单日可用数量</div>
             <div class="detail-value">
-              {{ voucherModel.singleCanUse + "张" || "--" }}
+              {{ voucherModel.singleCanUse ? voucherModel.singleCanUse + "张" : "--" }}
             </div>
           </div>
           <!-- 限购数量 -->
           <div class="detail-item">
             <div class="detail-label">限购数量</div>
             <div class="detail-value">
-              {{ voucherModel.purchaseLimitCode + "张" || "--" }}
+              {{ voucherModel.purchaseLimitCode ? voucherModel.purchaseLimitCode + "张" : "--" }}
             </div>
           </div>
           <!-- 适用范围 -->