Add devise helper to transit app
user
```ruby
module DeviseHelper
  def devise_error_messages!

    return "" if resource.errors.empty?

    messages = resource.errors.full_messages.map {|msg| content_tag(:li, msg)}.join
    sentence = I18n.t("errors.messages.not_saved", :count => resource.errors.count, :resource => resource.class.model_name.human.downcase)

    html = <<-HTML
    <div id="error_explanation">
      <h2>#{sentence}</h2>
      <ul>#{messages}</ul>
    </div>
    HTML

    ""
  end

end
```
assistant