refactor: supprimer tout le code legacy MVC/Twig/Stimulus

Supprime toutes les couches pré-DDD pour ne garder que l'architecture
hexagonale (src/Domain/), les entités Doctrine et le front Vue.js SPA.

Supprimé :
- src/Controller/ (9 controllers Twig, garde SecurityController)
- src/Service/, src/Message/, src/MessageHandler/ (services et messages legacy)
- src/Manager/, src/Twig/, src/Form/ (UI legacy)
- src/Event/, src/EventListener/, src/EventSubscriber/QueueStatusSubscriber
- src/Client/MangadexClient.php (doublon du Domain)
- src/Interface/, src/Factory/, src/DataFixtures/, src/Scheduler/MainSchedule
- templates/ (tous sauf vue/ et base retiré — SecurityController = pur JSON)
- assets/controllers/ (20 Stimulus controllers), app.js, bootstrap.js, controllers.json

Modifié :
- config/routes.yaml : suppression du chargement des controllers legacy
- config/packages/messenger.yaml : suppression des routes legacy
- config/services.yaml : suppression des bindings legacy + entrées Domain\Import fantômes
- webpack.config.js : suppression entry 'app' et enableStimulusBridge
- src/Entity/Chapter.php : suppression #[Broadcast] (Turbo Streams legacy)

Déplacé :
- src/Factory/*.php → tests/Factory/ (namespace App\Tests\Factory)

tests/Feature/Manga/DownloadVolumeTest.php

@@ -3,8 +3,8 @@
 namespace App\Tests\Feature\Manga;
 
 use App\Entity\Chapter;
-use App\Factory\ChapterFactory;
-use App\Factory\MangaFactory;
+use App\Tests\Factory\ChapterFactory;
+use App\Tests\Factory\MangaFactory;
 use App\Tests\Feature\AbstractApiTestCase;
 use Symfony\Component\HttpFoundation\Response;
 use Zenstruck\Foundry\Test\Factories;