平台订单详情：查看已同步订阅链接 back 口径与去嵌套对齐

tests/Feature/AdminPlatformOrderShowViewSyncedSubscriptionLinkUsesOrderShowSelfAsBackTest.php

@@ -0,0 +1,89 @@
+<?php
+
+namespace Tests\Feature;
+
+use App\Models\Merchant;
+use App\Models\Plan;
+use App\Models\PlatformOrder;
+use App\Models\SiteSubscription;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Illuminate\Support\Arr;
+use Tests\TestCase;
+
+class AdminPlatformOrderShowViewSyncedSubscriptionLinkUsesOrderShowSelfAsBackTest 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_view_synced_subscription_link_should_use_order_show_self_as_back_without_nested_back(): void
+    {
+        $this->loginAsPlatformAdmin();
+
+        $merchant = Merchant::query()->firstOrFail();
+        $plan = Plan::query()->create([
+            'code' => 'po_show_view_synced_sub_back_plan',
+            'name' => '平台订单详情查看已同步订阅 back 口径测试套餐',
+            'billing_cycle' => 'monthly',
+            'price' => 10,
+            'list_price' => 10,
+            'status' => 'active',
+            'sort' => 10,
+            'published_at' => now(),
+        ]);
+
+        $sub = SiteSubscription::query()->create([
+            'merchant_id' => $merchant->id,
+            'plan_id' => $plan->id,
+            'status' => 'activated',
+            'source' => 'manual',
+            'subscription_no' => 'SUB_PO_SHOW_VIEW_SYNCED_BACK_0001',
+            'plan_name' => $plan->name,
+            'billing_cycle' => $plan->billing_cycle,
+            'period_months' => 1,
+            'amount' => 10,
+            'starts_at' => now()->subDay(),
+            'ends_at' => now()->addMonth(),
+            'activated_at' => now()->subDay(),
+        ]);
+
+        $order = PlatformOrder::query()->create([
+            'merchant_id' => $merchant->id,
+            'plan_id' => $plan->id,
+            'site_subscription_id' => $sub->id,
+            'order_no' => 'PO_SHOW_VIEW_SYNCED_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' => [],
+        ]);
+
+        // 模拟从列表进入详情页，携带 back
+        $res = $this->get('/admin/platform-orders/' . $order->id . '?back=' . urlencode('/admin/platform-orders?status=pending'));
+        $res->assertOk();
+
+        // “查看已同步订阅”链接的 back 应该回到订单详情自身（不带外层 back），且不应出现 back 嵌套
+        $expectedBack = '/admin/platform-orders/' . $order->id;
+        $expectedUrl = '/admin/site-subscriptions/' . $sub->id . '?' . Arr::query([
+            'back' => $expectedBack,
+        ]);
+
+        $res->assertSee($expectedUrl, false);
+        $res->assertDontSee('back%3D', false);
+    }
+}