chore(admin-ui): migrate merchants index to filters/list card and admin pagination

tests/Feature/AdminMerchantsIndexShouldUseFiltersAndListCardStructureTest.php

@@ -0,0 +1,45 @@
+<?php
+
+namespace Tests\Feature;
+
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Tests\TestCase;
+
+class AdminMerchantsIndexShouldUseFiltersAndListCardStructureTest 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_admin_merchants_index_should_use_filters_and_list_card_structure(): void
+    {
+        $this->loginAsPlatformAdmin();
+
+        $response = $this->get('/admin/merchants');
+        $response->assertOk();
+
+        // 护栏：站点管理页应使用统一 Filters Card + List Card 结构，便于全站后台观感一致。
+        $response->assertSee('filters-card', false);
+        $response->assertSee('filters-summary', false);
+        $response->assertSee('filters-body', false);
+        $response->assertSee('filters-grid', false);
+
+        $response->assertSee('list-card', false);
+        $response->assertSee('list-card-header', false);
+        $response->assertSee('list-card-body', false);
+        $response->assertSee('list-card-table', false);
+
+        // 分页统一：此页数据量可能不足导致 hasPages=false，因此用扫描型护栏断言。
+        $blade = file_get_contents(resource_path('views/admin/merchants/index.blade.php'));
+        $this->assertIsString($blade);
+        $this->assertStringContainsString("links('pagination.admin')", $blade);
+    }
+}