feat: Implement authentication and API proxy for user management

Commit notes

This commit introduces a comprehensive authentication system using OAuth, integrating Google sign-in functionality. It adds a new API proxy to handle requests to the backend, ensuring secure communication and token management. Additionally, it establishes user state management through a dedicated store, enhancing the user experience with features like login, logout, and session persistence. New components for the header and library views are also included, improving the overall application structure and user interface.