text: const keystone = require('keystone');
  const types = keystone.Field.Types;
  
  const User = new keystone.List('User', {
    label: '用户',
    plural: '用户',
    track: true,
    noedit: true,
    nodelete: true,
    map: { name: 'did' },
    searchFields: 'did name email',
    defaultSort: '-createdAt',
    schema: { collection: 'users' },
  });
  
  User.add({
    did: {
      type: types.Text,
      label: '用户ID',
      required: true,
      initial: true,
    },
    name: { type: types.Text, label: '用户名', required: false },
    email: { type: types.Text, label: '邮箱', required: false },
  });
  
  User.defaultColumns = 'did, name, email, createdAt, updatedAt';
  User.register();
  