feat(19-ui-integration): przycisk Drukuj, bulk print, kolejka wydruku

- Przycisk "Drukuj" w prepare.php i show.php z AJAX + duplikat protection
- Bulk print z listy zamówień (checkboxy + header action)
- Kolejka wydruku w Ustawienia > Drukowanie (filtr statusu, retry)
- POST /api/print/jobs/bulk endpoint (package_ids + order_ids)
- ensureLabel() auto-download przez ShipmentProviderRegistry
- Apaczka carrier_id = nazwa usługi, kolumna Przewoznik
- Tab persistence (localStorage), label file_exists check
- Fix use statement ApaczkaApiClient, redirect po utworzeniu przesyłki
- Phase 17 (receipt duplicate guard) + Phase 18 (print queue backend) docs

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/Modules/Accounting/ReceiptController.php

@@ -44,6 +44,8 @@ final class ReceiptController
             return Response::redirect('/orders/' . $orderId);
         }
 
+        $existingReceipts = $this->receipts->findByOrderId($orderId);
+
         $order = is_array($details['order'] ?? null) ? $details['order'] : [];
         $items = is_array($details['items'] ?? null) ? $details['items'] : [];
         $seller = $this->companySettings->getSettings();
@@ -67,6 +69,7 @@ final class ReceiptController
             'configs' => array_values($configs),
             'seller' => $seller,
             'totalGross' => $totalGross,
+            'existingReceipts' => $existingReceipts,
         ], 'layouts/app');
 
         return Response::html($html);