feat(shipments): add ShipmentProviderInterface and ShipmentProviderRegistry

- Introduced ShipmentProviderInterface to define the contract for shipment providers.
- Implemented ShipmentProviderRegistry to manage and retrieve shipment providers.
- Added a new tool for probing Apaczka order_send payload variants, enhancing debugging capabilities.

src/Modules/Shipments/AllegroShipmentService.php

@@ -13,7 +13,7 @@ use DateTimeImmutable;
 use RuntimeException;
 use Throwable;
 
-final class AllegroShipmentService
+final class AllegroShipmentService implements ShipmentProviderInterface
 {
     public function __construct(
         private readonly AllegroIntegrationRepository $integrationRepository,
@@ -25,6 +25,11 @@ final class AllegroShipmentService
     ) {
     }
 
+    public function code(): string
+    {
+        return 'allegro_wza';
+    }
+
     /**
      * @return array<int, array<string, mixed>>
      */