refactor(web): extract shared current_actor controller helper

lib/mv_web/controllers/member_pdf_export_controller.ex

@@ -10,10 +10,11 @@ defmodule MvWeb.MemberPdfExportController do
 
   require Logger
 
-  alias Mv.Authorization.Actor
   alias Mv.Membership.{MemberExport, MemberExport.Build, MembersPDF}
   alias MvWeb.Translations.MemberFields
 
+  import MvWeb.ControllerHelpers, only: [current_actor: 1]
+
   use Gettext, backend: MvWeb.Gettext
 
   @payload_required_message "payload required"
@@ -79,13 +80,6 @@ defmodule MvWeb.MemberPdfExportController do
     bad_request(conn, @payload_required_message)
   end
 
-  # --- Actor / auth ---
-
-  defp current_actor(conn) do
-    conn.assigns[:current_user]
-    |> Actor.ensure_loaded()
-  end
-
   defp forbidden(conn) do
     conn
     |> put_status(:forbidden)