chore: Add permissions to auth data (#9695)

This API change sets the foundation for an upcoming frontend update, transitioning from a role-based model to a permission-based model. This new approach will determine eligibility for various actions and UI elements based on specific permissions rather than roles, enhancing flexibility and security in user access management.

app/models/account_user.rb

@@ -49,6 +49,10 @@ class AccountUser < ApplicationRecord
     ::Agents::DestroyJob.perform_later(account, user)
   end
 
+  def permissions
+    administrator? ? ['administrator'] : ['agent']
+  end
+
   def push_event_data
     {
       id: id,