- Extract resource_metadata URL from WWW-Authenticate and follow RFC 9728 chain
- Add buildWellKnownUrls with path-prefixed well-known fallback for gateways
- Fix resolveRegistrationEndpoint to try path-prefixed well-known (was missing await)
- Support relative Mcp-Auth-Server URL resolution against server URL
- Pass resourceMetadataUrl through all discoverOAuthEndpoints call sites
- Add comprehensive tests for path-prefixed, resource_metadata, and relative URL flows