support RFC8414 for OAuth 2.0 server metadata

[cardoe]

Preflight Checklist

• [x] I agree to follow the Code of Conduct that this project adheres to.
• [x] I have searched the issue tracker for an issue that matches the one I want to file, without success.

Problem Description

RFC8414 has come out to provide a well-known endpoint for OAuth 2.0. This is mostly intended for MCPs so this would be a bit of a forward looking feature.

Proposed Solution

Implement the well-known endpoint at /.well-known/oauth-authorization-server

Alternatives Considered

No response

Additional Information

No response

[johnvan7]

@cardoe I've create a PR for this feature: #4446 .