chore(admin-ui): dedupe orders show back links and keep context

resources/views/admin/orders/show.blade.php

@@ -7,6 +7,12 @@
 @php
     $incomingBack = (string) request()->query('back', '');
     $safeBackForLinks = \App\Support\BackUrl::sanitizeForLinks($incomingBack);
+
+    // back 参数用于“返回上一页（保留上下文）”，但 back 本身不应再包含 back（避免无限嵌套导致 URL 膨胀）
+    $selfWithoutBack = \App\Support\BackUrl::selfWithoutBack();
+
+    // 去重降噪：仅在没有 incoming back 时，提供“返回订单列表（保留上下文）”入口
+    $ordersIndexUrl = \App\Support\BackUrl::withBack('/admin/orders', $selfWithoutBack);
 @endphp
 
 <div class="page-header mb-20" data-page="admin.orders.show">
@@ -17,9 +23,10 @@
         </div>
         <div class="page-header-actions">
             @if($safeBackForLinks)
-                <a class="btn btn-secondary btn-sm" href="{!! $safeBackForLinks !!}">← 返回上一页（保留上下文）</a>
+                <a class="btn btn-secondary btn-sm" href="{!! $safeBackForLinks !!}">返回上一页（保留上下文）</a>
+            @else
+                <a class="btn btn-secondary btn-sm" href="{!! $ordersIndexUrl !!}">返回订单列表（保留上下文）</a>
             @endif
-            <a class="btn btn-secondary btn-sm" href="/admin/orders">返回订单列表</a>
         </div>
     </div>