feat: Add Google auth for User Login and Signup

[neeraj542]

Description:

Integrate Google OAuth to allow users to sign up and log in with their Google accounts. Ensure each user’s data is secure and only accessible to them. Update the UI with Google login options.

Acceptance Criteria:

• Integrate Google OAuth for auth (sign up and login).
• Upon authentication, create a user profile in the system tied to the Google account.
• Ensure each user can only access and manage their own data (income, expenses, goals, budgets, etc.).
• Provide a logout option.
• Secure all user data, following best practices for authentication and session management.
• Update the UI to include Google login/signup buttons.
• Display the authenticated user's name and email in the interface.

Optional:

• Consider using a library like Firebase Authentication, Auth0, or Passport.js for easier integration.
• Ensure the solution is mobile-responsive and works across devices.
• Document the setup and configuration steps in the README.

Tag me (@neeraj542 ) if any doubt you have.