Fix GitHub OAuth redirect flow and URL encoding

[Priyanshuthapliyal2005]

PR Fixes:

Fixed GitHub OAuth authentication by properly encoding redirect URI with encodeURIComponent() Improved error handling and added detailed logging for better debugging Enhanced GitHub link button component to prevent multiple clicks and improve UX Removed problematic setTimeout implementation causing redirect issues Fixed bcrypt implementation issues (removed mock-bcrypt.js) Made redirect URI handling more consistent and reliable across environments

Resolves #1823

Checklist before requesting a review

• [x] I have performed a self-review of my code
• [x] I assure there is no similar/duplicate pull request regarding same issue

https://github.com/user-attachments/assets/6452904b-d741-4c88-baba-93633a3dbcc9

[Priyanshuthapliyal2005]

@hkirat sir can you review this pr