平台订单详情：返回列表链接保留上下文（补测试）

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

@@ -787,6 +787,6 @@
         <span class="muted">｜</span>
     @endif
 
-    <a href="/admin/platform-orders">← 返回平台订单列表</a>
+    <a href="{!! $makePlatformOrderIndexUrl([]) !!}">← 返回平台订单列表（保留上下文）</a>
 </div>
 @endsection

tests/Feature/AdminPlatformOrderShowIndexLinkKeepsContextTest.php

@@ -0,0 +1,72 @@
+<?php
+
+namespace Tests\Feature;
+
+use App\Models\Merchant;
+use App\Models\Plan;
+use App\Models\PlatformOrder;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Illuminate\Support\Arr;
+use Tests\TestCase;
+
+class AdminPlatformOrderShowIndexLinkKeepsContextTest extends TestCase
+{
+    use RefreshDatabase;
+
+    protected function loginAsPlatformAdmin(): void
+    {
+        $this->seed();
+
+        $this->post('/admin/login', [
+            'email' => 'platform.admin@demo.local',
+            'password' => 'Platform@123456',
+        ])->assertRedirect('/admin');
+    }
+
+    public function test_show_page_index_link_should_contain_back_to_order_show(): void
+    {
+        $this->loginAsPlatformAdmin();
+
+        $merchant = Merchant::query()->firstOrFail();
+
+        $plan = Plan::query()->create([
+            'code' => 'po_show_index_link_back_plan',
+            'name' => '平台订单详情返回列表保留上下文测试套餐',
+            'billing_cycle' => 'monthly',
+            'price' => 10,
+            'list_price' => 10,
+            'status' => 'active',
+            'sort' => 10,
+            'published_at' => now(),
+        ]);
+
+        $order = PlatformOrder::query()->create([
+            'merchant_id' => $merchant->id,
+            'plan_id' => $plan->id,
+            'order_no' => 'PO_SHOW_INDEX_LINK_BACK_0001',
+            'order_type' => 'new_purchase',
+            'status' => 'pending',
+            'payment_status' => 'unpaid',
+            'plan_name' => $plan->name,
+            'billing_cycle' => $plan->billing_cycle,
+            'period_months' => 1,
+            'quantity' => 1,
+            'payable_amount' => 10,
+            'paid_amount' => 0,
+            'placed_at' => now(),
+            'meta' => [],
+        ]);
+
+        $res = $this->get('/admin/platform-orders/' . $order->id);
+        $res->assertOk();
+
+        $back = '/admin/platform-orders/' . $order->id;
+
+        $expectedIndexUrl = '/admin/platform-orders?' . Arr::query([
+            'back' => $back,
+        ]);
+
+        $res->assertSee('返回平台订单列表（保留上下文）');
+        $res->assertSee($expectedIndexUrl, false);
+    }
+}