refactor(tickets): 前端适配门票一次一单API

- createTicketOrder 去掉 quantity 参数
- toTicketOrder 去掉 quantity 映射
- 购票页循环创建 N 笔独立订单，提示逐笔支付

miniprogram/src/pages/comprehensive/tickets/index.vue

@@ -65,8 +65,15 @@ const submit = async () => {
   if (isSubmitting.value || !product.value?.is_active) return
   isSubmitting.value = true
   try {
-    const data = await ticketApi.createTicketOrder(quantity.value)
-    uni.navigateTo({ url: `/pages/comprehensive/pay/index?order_id=${data.order.id}` })
+    const orderIds = []
+    for (let i = 0; i < quantity.value; i++) {
+      const data = await ticketApi.createTicketOrder()
+      orderIds.push(data.order.id)
+    }
+    if (orderIds.length > 1) {
+      uni.showToast({ title: `已创建${orderIds.length}笔订单，请逐笔完成支付`, icon: 'none', duration: 2000 })
+    }
+    uni.navigateTo({ url: `/pages/comprehensive/pay/index?order_id=${orderIds[0]}` })
   } finally {
     isSubmitting.value = false
   }