Implement User Authentication and Google Sign-In Option

**Objective**: Implement Google Sign-In to allow users to authenticate and personalize their experience.

**Tasks**:
1. **Set Up Google Cloud**: Create a project and enable the Google Sign-In API.
2. **Obtain Credentials**: Generate OAuth 2.0 Client ID and secret.
3. **Integrate Frontend**:
- Add the Google Sign-In button.
- Handle authentication flow.
4. **Verify Token**: Authenticate users on the backend and manage sessions.
5. **Testing**: Ensure a smooth sign-in experience and handle errors.

**Note**: This feature will enhance user engagement by providing a seamless sign-in process. Contributions are welcome!