chore(admin-ui): unify list table empty state styling and class usage

tests/Feature/AdminBillingListsEmptyRowsShouldUseTableEmptyClassTest.php

@@ -0,0 +1,41 @@
+<?php
+
+namespace Tests\Feature;
+
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Tests\TestCase;
+
+class AdminBillingListsEmptyRowsShouldUseTableEmptyClassTest 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_billing_lists_empty_rows_should_use_table_empty_class(): void
+    {
+        $this->loginAsPlatformAdmin();
+
+        // 使用“不可能命中”的 keyword 强制列表进入空集合，从而验证空态 td 的统一 class。
+        $kw = '___no_such_keyword_' . uniqid() . '___';
+
+        $platformOrders = $this->get('/admin/platform-orders?keyword=' . urlencode($kw));
+        $platformOrders->assertOk();
+        $platformOrders->assertSee('table-empty', false);
+
+        $subscriptions = $this->get('/admin/site-subscriptions?keyword=' . urlencode($kw));
+        $subscriptions->assertOk();
+        $subscriptions->assertSee('table-empty', false);
+
+        $plans = $this->get('/admin/plans?keyword=' . urlencode($kw));
+        $plans->assertOk();
+        $plans->assertSee('table-empty', false);
+    }
+}