feat: unregister FCM token during logout.

src/app/logout/page.tsx

@@ -20,6 +20,14 @@ export default function LogoutPage() {
     hasStarted.current = true;
 
     const performLogout = async () => {
+      // Unregister FCM token before clearing auth (needs access token for API call)
+      try {
+        const { notificationService } = await import('@/services/notification.service');
+        await notificationService.unregister();
+      } catch {
+        // Best-effort — ignore errors
+      }
+
       // Clear localStorage
       localStorage.removeItem('accessToken');
       localStorage.removeItem('refreshToken');