- Add UsersService with create, read (getById, getByUsername, getByEmail, getAll), update (using mapper.partialUpdate), and delete methods
- Add UsersController with endpoints for all CRUD operations
- Add UsersRepository with custom queries for username and email
- Add UserDTO and NewUserDTO data transfer objects
- Add UsersMapper for entity-DTO conversions
- Add email domain validation (hittelco.com, accesscommunications.com)
- Add email uniqueness validation
- Create Postman collection for API testing with sample data
- Update Users model with timestamps and builder pattern