修复门票订单详情页 tickets 为 null 时的白屏崩溃，补 .gitignore

- 已退款/已下架订单后端返回 tickets 为 null，orderdetail 直接取
  obj.tickets.name 导致页面白屏崩溃
- 新增 ticketName 计算属性，回退订单快照 orderGoods.ticketsName；
  重新购买跳转回退 orderGoods.ticketsId
- 补 .gitignore 忽略 unpackage/ 与 .DS_Store

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.gitignore

@@ -1 +1,2 @@
 /unpackage/
+.DS_Store

pages/ticket/orderdetail.vue

@@ -17,7 +17,7 @@
 		<view class="detail_rq">
 			<text style="color: #000;line-height: 88rpx;font-size: 36rpx;font-weight: bold;">商品信息</text>
 			<view style="width: 702rpx;display: flex;justify-content: space-between;">
-				<text style="color: #000;font-weight: bold;">{{obj.tickets.name}}</text>
+				<text style="color: #000;font-weight: bold;">{{ticketName}}</text>
 				<u-icon name="arrow-right" color="#808080" size="24"></u-icon>
 			</view>
 
@@ -270,6 +270,11 @@
 			}
 		},
 		computed: {
+			// xuchao: 门票名称兜底 —— 已退款/下架订单 tickets 可能为 null，回退订单快照 orderGoods.ticketsName
+			ticketName() {
+				if (this.obj && this.obj.tickets) return this.obj.tickets.name
+				return this.obj && this.obj.orderGoods ? this.obj.orderGoods.ticketsName : ''
+			},
 			orderStatus() {
 				let str = ''
 				if (this.obj) {
@@ -365,8 +370,10 @@
 
 			},
 			aginPlay() {
+				// xuchao: tickets 可能为 null（已下架），回退订单快照 orderGoods.ticketsId
+				let ticketsId = this.obj.tickets ? this.obj.tickets.id : this.obj.orderGoods.ticketsId
 				uni.reLaunch({
-					url: 'scenicdetail?id=' + this.obj.tickets.id
+					url: 'scenicdetail?id=' + ticketsId
 				})
 			},
 			coyp(e) {