Added authentication flow (register, login, refresh token) with DTO-based validation and basic security constraints. The auth layer is now stable enough to unblock further work. Next focus is shifting away from infrastructure toward core system logic: defining responsibilities, domain rules, and actual behavior of the system rather than endpoints and plumbing. Authentication is treated as a solved baseline, not an area for feature creep, so future changes will prioritize business logic clarity and consistency over auth-related tweaks, btw on a photo there is my last pr to mostly complete authentication(most of it was cleaning my code and erasing redundancies)