feat: Add User-Agent header to Allegro API requests

- Implemented buildUserAgent() method in AllegroApiClient, AllegroOAuthClient, and AllegroTrackingService to include User-Agent header in all HTTP requests to Allegro API.
- Updated .env.example to include APP_VERSION and ALLEGRO_USER_AGENT_URL for configuration.
- Created public /info page to provide application details required by Allegro, including app name, version, description, and contact information.
- Added minimalist layout for public pages to ensure a professional appearance.
- Ensured all changes comply with Allegro's API requirements for User-Agent header.

src/Modules/Settings/ShopproOrdersSyncService.php

@@ -275,6 +275,7 @@ final class ShopproOrdersSyncService
                     'source' => 'shoppro',
                     'created' => $wasCreated,
                     'integration_id' => $integrationId,
+                    'new_payment_status' => (string) ($aggregate['order']['payment_status'] ?? ''),
                 ]);
             }
         } catch (Throwable $exception) {