Remove 'Créer votre article de présentation -' from form title

- Keep only user name in presentation form title
- Description remains below the title

components/AuthorPresentationEditor.tsx

@@ -154,7 +154,7 @@ function PresentationForm({
     >
       <div className="mb-6">
         <h2 className="text-2xl font-bold mb-2 text-neon-cyan font-mono">
-          {t('presentation.title')} - {userName}
+          {userName}
         </h2>
         <p className="text-cyber-accent text-sm">
           {t('presentation.description')}