Expose OAuth resource metadata endpoint

[RomanEmreis]

Description:

Automatically register the OAuth Protected Resource metadata endpoint as required by MCP.

Scope:

• Register /.well-known/oauth-protected-resource
• Populate fields from HttpTransport configuration:
  • canonical_uri
  • authorization_servers
  • scopes
• Ensure spec-compliant response format

Goal:

Make Neva HTTP transport a compliant OAuth resource server out of the box.