feat: Ajout d'un endpoint getBySlug

src/Domain/Manga/Infrastructure/Persistence/LegacyMangaRepository.php

@@ -53,6 +53,14 @@ readonly class LegacyMangaRepository implements MangaRepositoryInterface
         return $entity ? $this->toDomain($entity) : null;
     }
 
+    public function findBySlug(MangaSlug $slug): ?DomainManga
+    {
+        $entity = $this->entityManager->getRepository(EntityManga::class)
+            ->findOneBy(['slug' => $slug->getValue()]);
+
+        return $entity ? $this->toDomain($entity) : null;
+    }
+
     public function save(DomainManga $manga): void
     {
         $entity = new EntityManga();