When a Paybox callback confirms payment on an order with status 4
(Annulé), the payment is still recorded but the order status is no
longer forced to « Préparation ». Instead, an alert email is sent to
``commande@jardinenvie.com`` warning that a refund is likely needed.
New ``AlertePaiementAnnule`` mailable with DB template providing order
ref, amount, customer info and payment reference. New method
``OrderMails::sendCancelledOrderPaymentAlert()`` handles the dispatch.
