✨ feat: added Github Enterprise SSO login

[rubentalstra]

Summary

Closes: #2812

Docs: LibreChat-AI/librechat.ai#217

This pull request enhances our GitHub OAuth integration by adding support for GitHub Enterprise authentication. When the environment variable GITHUB_ENTERPRISE_BASE_URL is provided, the GitHub strategy will automatically switch to using GitHub Enterprise endpoints. In addition, minor adjustments have been made to the social login registration to ensure everything integrates smoothly.

Key Changes

• Environment Variables:
  The example configuration now includes (commented) variables for GitHub Enterprise:

  • GITHUB_ENTERPRISE_BASE_URL
  • GITHUB_ENTERPRISE_USER_AGENT
    This allows users to optionally configure GitHub Enterprise without affecting the default GitHub login behavior.

• GitHub Strategy Update:
  In api/strategies/githubStrategy.js, the GitHub OAuth strategy now conditionally uses GitHub Enterprise endpoints if GITHUB_ENTERPRISE_BASE_URL is defined:

  • Authorization, Token, and Profile URLs: The endpoints for authorization, token exchange, user profile, and email retrieval are updated to use the enterprise base URL.
  • Custom User Agent: If GITHUB_ENTERPRISE_USER_AGENT is set, it is passed along in the request options.

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Change Type

• New feature (non-breaking change which adds functionality)

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Testing

Test Configuration:

1. Environment Setup:
   • In your .env or configuration file, enable GitHub Enterprise support by setting the following variables:

     GITHUB_ENTERPRISE_BASE_URL=https://your-ghe-instance.com
     GITHUB_ENTERPRISE_USER_AGENT=YourEnterpriseAppName

   • Leave the standard GitHub variables as they are if you also require regular GitHub authentication.

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Checklist

• My code adheres to this project's style guidelines.
• I have performed a self-review of my code.
• I have commented any non-obvious sections of code.
• I have updated the example environment configuration.
• My changes do not introduce new warnings.
• I have written tests to cover my changes.
• All local unit tests pass with my changes.
• Any dependent changes in downstream modules have been merged and published.

[rubentalstra]

Going to refactor this so it would be or the normal GitHub url or a custom url.

I think this is a better strategy then adding another auth option.

[rubentalstra]

refactoring done.