fix(order-detail): restore divider between pay amount and bind/refund time

Remove detail-row--last from pay amount row so the border appears
when activatedTime or refundedTime rows are conditionally shown.

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

src/packages/user/pages/order/detail.vue

@@ -48,7 +48,7 @@
         <text class="detail-label">支付渠道</text>
         <text class="detail-value">{{ order.payChannel }}</text>
       </view>
-      <view class="detail-row detail-row--last">
+      <view class="detail-row">
         <text class="detail-label">支付金额</text>
         <text class="detail-value detail-value--price">¥{{ order.payAmount }}.00</text>
       </view>