Update user

priv/repo/migrations/20250615131158_create_users.exs

@@ -9,12 +9,7 @@ defmodule Nulla.Repo.Migrations.CreateUsers do
       add :privateKeyPem, :string
       add :last_active_at, :utc_datetime
 
-      add :actor_id, references(:actors, column: :id, type: :bigint, on_delete: :delete_all),
-        null: false
-
       timestamps(type: :utc_datetime)
     end
-
-    create unique_index(:users, [:actor_id])
   end
 end