feat(data): Add local user data layer
What does this MR do?
- Implements the foundation for local user management.
- Adds a
UserEntityfor the Room database. - Adds a
UserDaowith methods to insert and find users. - Adds a
UserRepositorywithloginandregisterfunctions. - Includes a unit test for
UserRepositoryImplto verify the logic.
Why was this change needed?
This is the core data layer required for the upcoming user authentication feature. It is independent of the UI and provides the necessary engine for managing users locally.