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)

webpack.config.js

@@ -20,12 +20,7 @@ Encore
      * Each entry will result in one JavaScript file (e.g. app.js)
      * and one CSS file (e.g. app.css) if your JavaScript imports CSS.
      */
-    .addEntry('app', './assets/app.js')
     .addEntry('vue-app', './assets/vue/app/index.js')
-    // .addEntry('alpine', 'alpinejs')
-
-    // enables the Symfony UX Stimulus bridge (used in assets/bootstrap.js)
-    .enableStimulusBridge('./assets/controllers.json')
 
     // When enabled, Webpack "splits" your files into smaller pieces for greater optimization.
     .splitEntryChunks()