fix: duplikaty zamowien + status COD (is_cod flag)

- summaryView(): guard — redirect do istniejacego zamowienia gdy ORDER_SUBMIT_LAST_ORDER_ID w sesji
- basketSave(): try-catch wokol createFromBasket(), wyjatki logowane, koszyk zachowany
- OrderRepository: usunieto hardkodowane payment_id == 3, uzywana flaga is_cod
- PaymentMethodRepository: nowe pole is_cod w normalizacji, save() i forTransport() SQL
- ShopPaymentMethodController: switch "Platnosc przy odbiorze" w formularzu edycji
- migrations/0.338.sql: ALTER TABLE pp_shop_payment_methods ADD COLUMN is_cod

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

autoload/admin/Controllers/ShopPaymentMethodController.php

@@ -184,6 +184,7 @@ class ShopPaymentMethodController
             'apilo_payment_type_id' => $paymentMethod['apilo_payment_type_id'] ?? '',
             'min_order_amount' => $paymentMethod['min_order_amount'] ?? '',
             'max_order_amount' => $paymentMethod['max_order_amount'] ?? '',
+            'is_cod' => (int)($paymentMethod['is_cod'] ?? 0),
         ];
 
         $fields = [
@@ -220,6 +221,10 @@ class ShopPaymentMethodController
                 'tab' => 'settings',
                 'options' => $apiloOptions,
             ]),
+            FormField::switch('is_cod', [
+                'label' => 'Platnosc przy odbiorze',
+                'tab' => 'settings',
+            ]),
             FormField::switch('status', [
                 'label' => 'Aktywny',
                 'tab' => 'settings',