Mejoras visuales

Mi solucion al reto
En el controlador

    #[Route('/blog/{slug}', name: 'app_post')]
    public function post($slug, PostRepository $postRepository): Response
    {
        return $this->render('page/post.html.twig', [
            'post' => $postRepository->findOneBySlug($slug),
            'form' => $this->createForm(CommentType::class),
        ]);
    }

En el repositorio

    public function findOneBySlug($slug): ?Post
    {
        return $this->createQueryBuilder('post')
            ->andWhere('post.slug = :slug')
            ->setParameter('slug', $slug)
            ->addSelect(['comments', 'category', 'user'])
            ->leftJoin('post.comments', 'comments')
            ->leftJoin('comments.user', 'user')
            ->leftJoin('post.category', 'category')
            ->getQuery()
            ->getOneOrNullResult();
    }