Add user type support and update auth/profile APIs

Refactor User and Authentication models for clarity and extensibility

Refactor DTOs and streamline user-related logic

Add user profile management and integrate with authentication

Refactor authentication flow and enhance security setup

Add JWT-based security and refactor application setup

Implement user registration, login flow, and exception handling

Rename project and package from SpringBootLab to SideFlow

Add foundational user authentication and role management

Rename project and package from SpringBootLab to SideFlow

Add initial Spring Boot project setup