fix: change button variant from 'default' to 'primary' in test-tickets page

The Button component only accepts: 'primary' | 'secondary' | 'outline' |
'danger' | 'success'. Changed 'default' to 'primary' as the closest equivalent.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

app/test-tickets/page.tsx

@@ -22,7 +22,7 @@ export default function TestTicketsPage() {
       title: "Scénario 1 : Nouveau ticket",
       description: "Génère un nouveau code unique que vous pouvez utiliser",
       action: "Générer un code",
-      buttonVariant: "default" as const,
+      buttonVariant: "primary" as const,
       onClick: () => {
         const code = generateTestCode();
         alert(`Code généré : ${code}\n\nCopiez ce code et utilisez-le sur la page /jeux`);