Create FormObject for plan nodes in admin
user
```ruby
# frozen_string_literal: true

module GobiertoAdmin
  module GobiertoPlans
    class NodeForm < BaseForm

      attr_accessor(
        :id,
        :plan_id,
        :category_id,
        :name_translations,
        :status_translations,
        :progress,
        :starts_at,
        :ends_at,
        :options
      )

      validates :plan, :category, :name_translations, presence: true

      delegate :persisted?, to: :node

      def save
        save_node if valid?
      end

      def plan
        @plan ||= ::GobiertoPlans::Plan.find_by(id: plan_id)
      end

      def node
        @node ||= ::GobiertoPlans::Node.find_by(id: id).presence || build_node
      end
      alias record node

      def category
        @category ||= plan.categories.find_by(id: category_id) || node.categories.where(vocabulary: plan.categories_vocabulary).first
      end

      private

      def build_node
        ::GobiertoPlans::Node.new
      end

      def save_node
        @node = node.tap do |attributes|
          attributes.name_translations = name_translations
          attributes.status_translations = status_translations
          attributes.progress = progress
          attributes.starts_at = starts_at
          attributes.ends_at = ends_at
          attributes.options = options
        end

        if @node.valid?
          @node.save
          unless @node.categories.include? category
            @node.categories.where(vocabulary: plan.categories_vocabulary).each do |plan_category|
              @node.categories.delete plan_category
            end
            node.categories << category
          end

          @node
        else
          promote_errors(@node.errors)

          false
        end
      end
    end
  end
end
```
assistant