- Create UserController, WorkoutController, and SessionController to expose application use cases via REST endpoints
- Add request and response DTOs alongside web mappers for the User, Workout, and Session domains
- Introduce GlobalExceptionHandler to handle domain-specific exceptions and return HTTP 400 Bad Request responses
- Add Springdoc OpenAPI and Scalar dependencies to build.gradle for API documentation
- Configure OpenAPI and Scalar settings in the base and dev application properties