Implement cookie based tracking

[loftwah]

We can add support for cookies in the page tracking middleware, update the pageview model and also the analytics controller so we can leverage the new data.

rails generate migration AddCookieValueToPageViews cookie_value:string

class AddCookieValueToPageViews < ActiveRecord::Migration[7.1]
  def change
    add_column :page_views, :cookie_value, :string
    add_index :page_views, :cookie_value
  end
end

class PageView < ApplicationRecord
  belongs_to :user

  validates :cookie_value, presence: true
  # Optionally, if you want to enforce uniqueness:
  # validates :cookie_value, uniqueness: { scope: [:user_id, :path] }
end

[loftwah]

ChatGPT that discusses this.