* Add error handling for JSON encoding and HTTP server calls.
* Update passkey examples to improve readability and maintainability.
* Ensure consistent use of error handling across all examples.
* Introduce OAuth2 authentication examples for Google, GitHub, and custom providers.
* Implement OAuth2 methods for handling authentication, token refresh, and logout.
* Create a flexible structure for supporting multiple OAuth2 providers.
* Enhance DatabaseAuthenticator to manage OAuth2 sessions and user creation.
* Add database schema setup for OAuth2 user and session management.
