chore(admin): remove tenants placeholder view without routes

tests/Feature/AdminNoTenantsPlaceholderBladeTest.php

@@ -0,0 +1,16 @@
+<?php
+
+namespace Tests\Feature;
+
+use Illuminate\Support\Facades\File;
+use Tests\TestCase;
+
+class AdminNoTenantsPlaceholderBladeTest extends TestCase
+{
+    public function test_admin_tenants_placeholder_view_should_not_exist_anymore(): void
+    {
+        $path = resource_path('views/admin/tenants/index.blade.php');
+
+        $this->assertFalse(File::exists($path), 'tenants 占位页面已弃用，应删除，避免产生“有页面无路由”的困惑。');
+    }
+}