feat: GetManga endpoint + tests

src/Domain/Manga/Application/Response/MangaResponse.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace App\Domain\Manga\Application\Response;
+
+readonly class MangaResponse
+{
+    public function __construct(
+        public string $id,
+        public string $title,
+        public string $slug,
+        public string $description,
+        public string $author,
+        public int $publicationYear,
+        public array $genres,
+        public string $status,
+        public ?string $externalId,
+        public ?string $imageUrl,
+        public ?float $rating
+    ) {}
+}