feat(admin): 绑定订阅后回跳提示增强（attached_subscription + 滚动）

tests/Feature/AdminPlatformOrderAttachSubscriptionRedirectShouldCarryAttachedSubscriptionFlagTest.php

@@ -0,0 +1,84 @@
+<?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 Tests\TestCase;
+
+class AdminPlatformOrderAttachSubscriptionRedirectShouldCarryAttachedSubscriptionFlagTest 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_attach_subscription_should_redirect_to_order_show_with_attached_subscription_flag(): void
+    {
+        $this->loginAsPlatformAdmin();
+
+        $merchant = Merchant::query()->firstOrFail();
+
+        $plan = Plan::query()->create([
+            'code' => 'po_attach_sub_redirect_flag_plan',
+            'name' => '绑定订阅回跳标记测试套餐',
+            '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' => 'active',
+            'source' => 'manual',
+            'subscription_no' => 'SS_ATTACH_REDIRECT_0001',
+            'plan_name' => $plan->name,
+            'billing_cycle' => $plan->billing_cycle,
+            'period_months' => 1,
+            'amount' => 10,
+            'starts_at' => now()->subDays(1),
+            'ends_at' => now()->addDays(10),
+            'snapshot' => [],
+            'meta' => [],
+        ]);
+
+        $order = PlatformOrder::query()->create([
+            'merchant_id' => $merchant->id,
+            'plan_id' => $plan->id,
+            'order_no' => 'PO_ATTACH_REDIRECT_0001',
+            'order_type' => 'renewal',
+            'site_subscription_id' => null,
+            '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()->subMinutes(10),
+            'meta' => [],
+        ]);
+
+        $res = $this->post('/admin/platform-orders/' . $order->id . '/attach-subscription', [
+            'site_subscription_id' => $sub->id,
+            // 故意不给 back：应回跳到订单详情自身，并携带 attached_subscription=1
+        ]);
+
+        $res->assertRedirect('/admin/platform-orders/' . $order->id . '?attached_subscription=1');
+    }
+}