update server examples to cover external authentication servers #658
Description
Is your feature request related to a problem? Please describe.
RFC 8707
Describe the solution you'd like
Add a new example forked from src/examples/server/simpleStreamableHttp.ts to support an external authentication server (AS).
May want to cater to JWT cases and/or absence of the (optional) introspection_endpoint & revocation_endpoint.
Describe alternatives you've considered
Modifying simpleStreamableHttp to optionally support an external AS would probably trigger a rename to complexStreamableHttp 🙈
Additional context
Beyond external AS, a new example could be used as a testing ground for OICD support (see modelcontextprotocol/modelcontextprotocol#677)