- Introduced a comprehensive Signin API for user authentication, supporting multiple OAuth providers (Google, GitHub, Microsoft, Apple).
- Updated the file management API endpoints to use a singular `/file` path instead of `/files`, enhancing consistency across the API.
- Revised README documentation to include detailed descriptions of the new Signin API and updated file management endpoints.
- Enhanced test cases to reflect the changes in endpoint structure and ensure robust coverage for the new Signin functionality.
