Updated `decode_token` for stricter validation of token claims and explicit error handling. Added utilities for token revocation and verification, improving
Introduced unit tests for `get_current_user`, `get_current_active_user`, and security functions like token creation and decoding. Also refactored imports for consistency and cleaned up unused or misplaced code to improve maintainability.
Introduces schemas for user management, token handling, and password hashing. Implements routes for user registration, login, token refresh, and user info retrieval. Sets up authentication dependencies and integrates the API router with the application.
