- Add Timber to technical decisions in tech_spec.txt
- Update feature statuses to 'backend_implemented' in tech_spec.txt
- Update UI component statuses to 'needs_review' in project_structure.txt
- Add SetupScreen with UI for server URL, username, and password input.
- Make SetupScreen the initial screen in the navigation graph.
- Implement secure credential storage using EncryptedSharedPreferences.
- Create CredentialsRepository and AuthRepository to manage credentials and auth tokens.
- Add LoginUseCase to handle the business logic for logging in.
- Implement a temporary Retrofit client in ItemRepository to handle login against a user-provided URL.
- Integrate login logic into SetupViewModel.
- Update all relevant project documentation and DI modules.
