* feat: add OAuth extension hooks for MCP authentication
Add extension points in core that allow cloud extensions to support
OAuth 2.1 (RFC 9728 / RFC 7591) for MCP server authentication:
- HttpExtension.get_root_router() for well-known endpoint mounting
- AuthenticationError.headers for WWW-Authenticate propagation
- MCP middleware forwards auth error headers to clients
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
* docs: document get_root_router and AuthenticationError.headers
Add documentation for the new extension points introduced in the
OAuth extension hooks commit.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
* Remove OAuth-specific wording from extension docs
Make the AuthenticationError headers example generic instead of
OAuth-specific, since these are general-purpose extension hooks.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
