平台订单详情：存在退款/回执差额时禁用BMPA按钮并加护栏测试

tests/Feature/AdminPlatformOrderShowMarkPaidAndActivateButtonDisabledWhenRefundExistsTest.php

@@ -0,0 +1,78 @@
+<?php
+
+namespace Tests\Feature;
+
+use App\Models\Merchant;
+use App\Models\Plan;
+use App\Models\PlatformOrder;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Tests\TestCase;
+
+class AdminPlatformOrderShowMarkPaidAndActivateButtonDisabledWhenRefundExistsTest 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_mark_paid_and_activate_button_should_be_disabled_when_refund_exists(): void
+    {
+        $this->loginAsPlatformAdmin();
+
+        $merchant = Merchant::query()->firstOrFail();
+        $plan = Plan::query()->create([
+            'code' => 'po_show_disable_bmpa_refund_plan',
+            'name' => '订单详情禁用BMPA-退款存在测试套餐',
+            '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_DISABLE_BMPA_REFUND_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' => [
+                'refund_receipts' => [
+                    [
+                        'type' => 'refund',
+                        'channel' => 'offline',
+                        'amount' => 1,
+                        'refunded_at' => now()->toDateTimeString(),
+                        'note' => 'test-refund',
+                        'created_at' => now()->toDateTimeString(),
+                        'admin_id' => 1,
+                    ],
+                ],
+            ],
+        ]);
+
+        $res = $this->get('/admin/platform-orders/' . $order->id);
+        $res->assertOk();
+
+        // 按现有页面渲染：应包含 disabled 属性（前端阻断，后端仍有安全阀）
+        $res->assertSee('action="/admin/platform-orders/' . $order->id . '/mark-paid-and-activate"', false);
+        $res->assertSee('标记支付并生效', false);
+        $res->assertSee('disabled', false);
+    }
+}