feat(02-purchase-event-prepayment): move purchase event to przelewy24 pre-payment page

Phase 2 complete:
- buildPurchaseDataLayer() called in przelewy24() controller, payload passed to template
- dataLayer.push added to templates/tickets/przelewy24.php (fires at order commitment)
- dataLayer.push removed from templates/tickets/order-confirm.php
- Captures 100% of orders regardless of user returning from payment gateway

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

autoload/controls/class.Tickets.php

@@ -650,11 +650,14 @@ class Tickets
     $przelewy24_hash = md5(time());
     $mdb->update('orders', ['payment_hash' => $przelewy24_hash], ['id' => $order['id']]);
 
+    $purchaseDataLayer = self::buildPurchaseDataLayer($order);
+
     return \Tpl::view('tickets/przelewy24', [
       'settings' => $settings,
       'hash' => \S::get('order'),
       'order' => $order,
-      'przelewy24_hash' => $przelewy24_hash
+      'przelewy24_hash' => $przelewy24_hash,
+      'purchase_data_layer' => $purchaseDataLayer
     ]);
   }
 
@@ -847,14 +850,12 @@ class Tickets
     $order = \factory\Tickets::get_order_details_by_hash(\S::get('order'));
     $order_successful = false;
     $order_fail = false;
-    $purchaseDataLayer = null;
 
     if ( $order && !empty($order['payment_status']) && empty($order['informed_user']) )
     {
       if ($order['payment_status'])
       {
         $order_successful = true;
-        $purchaseDataLayer = self::buildPurchaseDataLayer($order);
         $mailSent = self::sendPaidOrderSummaryEmail($order);
         if ($mailSent) {
           $mdb->update('orders', ['informed_user' => 1], ['id' => $order['id']]);
@@ -871,7 +872,7 @@ class Tickets
       'order' => $order,
       'order_successful' => $order_successful,
       'order_fail' => $order_fail,
-      'purchase_data_layer' => $purchaseDataLayer
+      'purchase_data_layer' => null
     ]);
   }