1. Project setup — backend init, MongoDB connect, folder structure
2. User model + Register/Login endpoints + JWT
3. Todo model + full CRUD endpoints + middleware
4. React project setup + routing + Tailwind
5. Auth UI (Login/Register forms, AuthContext)
6. Todo UI (list, create, update, delete, toggle)
7. Filtering, priority, due dates
8. Polish — responsive design, UX details
9. Polish — responsive design, UX details