feat: 增强管理员权限管理，添加 RBAC 支持，更新 AdminUser 模型以处理角色和权限，更新登录接口返回权限信息，扩展数据库填充器以同步角色权限

tests/Feature/AdminAuthLoginTest.php

@@ -37,7 +37,7 @@ test('admin login returns bearer token when captcha passes validation', function
         ->assertJsonPath('code', ErrorCode::Success->value)
         ->assertJsonPath('data.admin.username', 'tester')
         ->assertJsonPath('data.admin.nickname', '测试昵称')
-        ->assertJsonStructure(['data' => ['token', 'token_type', 'admin' => ['id', 'username', 'nickname', 'email']]]);
+        ->assertJsonStructure(['data' => ['token', 'token_type', 'admin' => ['id', 'username', 'nickname', 'email', 'permissions']]]);
 
     $token = $resp->json('data.token');
     expect($token)->not->toBeNull();