Update email recipient logic for wash certificate bookings

- Added conditional logic to prioritize `wash_certificate_email` if provided for customer notifications.
- Refactored email setup to use the selected email for wash certificate-related bookings.

services/nginx/app/classes/email.php

@@ -348,6 +348,10 @@ class email implements email_i
         $customer->requireSelected();
         $recipient_name = $customer->getCustomerName((int)$customer->customer_number->value());
         $recipient_email = $customer->email->value();
+        // Check if the customer has a booking-specific email provided
+        if (!empty($customer->wash_certificate_email->value())) {
+            $recipient_email = (string)$customer->wash_certificate_email->value();
+        }
         // Get the department details
         $department = (new departments_o())->select((int)$order_booking->department->value());
         $department->requireSelected();
@@ -363,7 +367,7 @@ class email implements email_i
             $order_booking->reg_1->value(),
             $order_booking->reg_2->value(),
             ($order_booking->containsWashCertificateItem() ? 'Ja' : 'Nej'),
-            $customer->email->value(), // Wash certificate email is the customer's email
+            $recipient_email,
             $order_booking->datetime->value(),
             (string)$department->getDepartmentName((int)$department->id),
             (string)$department->getBranding()->address->value(),