How to eager load AR associations when using Elasticsearch-rails and Kaminari

eager_pagination.rb

class EagerPagination < SimpleDelegator
  attr_reader :records, :scope

  def initialize(records, scope)
    super(records)
    @records = records
    @scope = scope
  end

  def each
    records.public_send(scope).each do |r|
      yield r
    end
  end
end

example_controller.rb

class GiftsController < ApplicationController
  def index
    records = Gift.search('flower').page(params[:page]).records
    @gifts = EagerPagination.new(records, :eager)
  end
  
  # Breaks when using Kaminari pagination because the `page`
  # decorator is lost on `.includes(:user)`
  def failing_index
    @gifts = Gift.search('flower')
      .page(params[:page]).records.includes(:user)
  end
end

gift.rb

class Gift
  include Elasticsearch::Model
  belongs_to :user
  
  scope :eager, -> { includes(:user) }
end