feat(platform-orders): 同步失败数摘要卡数字支持一键跳转筛选（含测试）

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

@@ -128,7 +128,9 @@
     </div>
     <div class="card">
         <h3>同步失败数</h3>
-        <div class="metric-number">{{ $summaryStats['failed_sync_orders'] ?? 0 }}</div>
+        <div class="metric-number">
+            <a class="link" href="{{ request()->fullUrlWithQuery(['sync_status' => 'failed', 'page' => null]) }}">{{ $summaryStats['failed_sync_orders'] ?? 0 }}</a>
+        </div>
     </div>
     <div class="card">
         <h3>可同步订单</h3>

tests/Feature/AdminPlatformOrderFailedSyncSummaryCardLinkTest.php

@@ -0,0 +1,31 @@
+<?php
+
+namespace Tests\Feature;
+
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Tests\TestCase;
+
+class AdminPlatformOrderFailedSyncSummaryCardLinkTest 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_platform_orders_page_shows_failed_sync_summary_card_link(): void
+    {
+        $this->loginAsPlatformAdmin();
+
+        $this->get('/admin/platform-orders')
+            ->assertOk()
+            ->assertSee('同步失败数')
+            ->assertSee('sync_status=failed');
+    }
+}