✨ Implement Google OAuth authentication and event claiming functionality
- Added Google OAuth integration with OmniAuth for user authentication.
- Created Users table with fields for email, name, Google ID, and avatar URL.
- Updated Events table to include a user reference for claimed events.
- Implemented SessionsController for handling sign-in, sign-out, and failure actions.
- Created EventClaimsController to manage claiming events by users.
- Updated views for sign-in, event claiming, and event management.
- Enhanced header and footer for user authentication state.
- Added routes for authentication and event claiming.
- Configured OmniAuth initializer for Google OAuth.
- Updated application layout and styles for improved user experience.