[FEATURE] Add Google Auth for easy signup and signin alongside username login

[Anikesh02]

Feature Description

Add Google Authentication to SDEverse, enabling users to sign up and sign in using their Google accounts in addition to traditional username-based login.

Problem/Motivation

Currently, users can only sign up and log in using a username. Integrating Google Auth will provide an easier and faster authentication process, especially for new users. This will also improve user convenience and lower the barrier for new signups, especially relevant during events like Hacktoberfest.

Proposed Solution

• Integrate Google OAuth 2.0 authentication into the existing authentication system.
• Allow users to choose between Google login or username/password login on both the signup and signin pages.
• Ensure the backend securely handles tokens and user information from Google.
• Maintain compatibility for users who prefer traditional username login.
• Update UI with a "Continue with Google" button.

Alternatives Considered

• Adding support for other OAuth providers (GitHub, Facebook) for broader social login options.
• Using only Google Auth (not recommended due to exclusion of non-Google users).

This feature will make SDEverse more accessible and attractive, especially for contributors during Hacktoberfest 2025.
@Harshdev625 , I would like to work on this as my contribution for Hacktoberfest.
Kindly assign this task to me

[Harshdev625]

@Anikesh02 I’ve assigned this issue to you.
Feel free to start working on it , let me know if you need any clarification or context before beginning.

[Anikesh02]

@Harshdev625 Sure

[Harshdev625]

@Anikesh02 Any updates on this issue? Just checking in to see the progress.

[Anikesh02]

@Harshdev625 I have added a #261 PR. Kindly review it.

[Sudeepthi-Mounika]

can you please assign this issue to me