fix: eBay config CRUD — override createEntity() for required constructor args

EasyAdmin calls new ArticleTypePlatformConfig() with no args. Fix:
- Add setArticleType() setter to the entity
- Override createEntity() in the CRUD controller to inject the eBay Platform
  and first available ArticleType as placeholder (form overwrites both)

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

src/Domain/Channel/ArticleTypePlatformConfig.php

@@ -65,6 +65,11 @@ class ArticleTypePlatformConfig
         return $this->articleType;
     }
 
+    public function setArticleType(ArticleType $articleType): void
+    {
+        $this->articleType = $articleType;
+    }
+
     public function getPlatform(): Platform
     {
         return $this->platform;

src/Infrastructure/Http/Controller/Admin/EbayArticleTypePlatformConfigCrudController.php

@@ -4,7 +4,9 @@ declare(strict_types=1);
 
 namespace App\Infrastructure\Http\Controller\Admin;
 
+use App\Domain\Article\Repository\ArticleTypeRepositoryInterface;
 use App\Domain\Channel\ArticleTypePlatformConfig;
+use App\Domain\Channel\Repository\PlatformRepositoryInterface;
 use App\Infrastructure\Channel\Ebay\EbayPolicyProvider;
 use Doctrine\ORM\QueryBuilder;
 use EasyCorp\Bundle\EasyAdminBundle\Collection\FieldCollection;
@@ -21,8 +23,26 @@ use EasyCorp\Bundle\EasyAdminBundle\Orm\EntityRepository;
 /** @extends AbstractCrudController<ArticleTypePlatformConfig> */
 final class EbayArticleTypePlatformConfigCrudController extends AbstractCrudController
 {
-    public function __construct(private readonly EbayPolicyProvider $policyProvider)
+    public function __construct(
+        private readonly EbayPolicyProvider $policyProvider,
+        private readonly PlatformRepositoryInterface $platformRepository,
+        private readonly ArticleTypeRepositoryInterface $articleTypeRepository,
+    ) {
+    }
+
+    public function createEntity(string $entityFqcn): ArticleTypePlatformConfig
     {
+        $platform = $this->platformRepository->findByType('ebay');
+        if (null === $platform) {
+            throw new \RuntimeException('eBay-Platform nicht in der Datenbank konfiguriert. Bitte zuerst eine Platform mit type="ebay" anlegen.');
+        }
+
+        $articleTypes = $this->articleTypeRepository->findAll();
+        if ([] === $articleTypes) {
+            throw new \RuntimeException('Kein Artikeltyp vorhanden. Bitte zuerst einen Artikeltyp anlegen.');
+        }
+
+        return new ArticleTypePlatformConfig($articleTypes[0], $platform, '');
     }
 
     public static function getEntityFqcn(): string