Split draft-spec scenarios into their own suite (#317)

* feat: split draft-spec scenarios into their own suite

- add --suite draft to the server command, selecting scenarios whose
  source.introducedIn is the draft protocol version
- exclude draft scenarios from the default active suite until the draft
  spec is published as a dated release
- derive the client command's draft suite from source.introducedIn so the
  non-auth draft scenarios (SEP-2243/2575/2322/2106) are included alongside
  the auth ones
- keep everything-server self-test coverage for draft scenarios in
  all-scenarios.test.ts (active + non-pending draft)
- document available suites in the README and add suite-membership tests

* fix: repair broken specReferences URLs

- SEP-986: SEP/SEP-986.md no longer exists in the spec repo; point at the
  Tool Names section of the published 2025-11-25 tools page instead
- SEP-990: the ext-auth spec file is enterprise-managed-authorization.mdx,
  not enterprise-oauth.mdx

Fixes #313

src/scenarios/client/auth/spec-references.ts

@@ -104,7 +104,7 @@ export const SpecReferences: { [key: string]: SpecReference } = {
   },
   SEP_990_ENTERPRISE_OAUTH: {
     id: 'SEP-990-Enterprise-Managed-OAuth',
-    url: 'https://github.com/modelcontextprotocol/ext-auth/blob/main/specification/draft/enterprise-oauth.mdx'
+    url: 'https://github.com/modelcontextprotocol/ext-auth/blob/main/specification/draft/enterprise-managed-authorization.mdx'
   },
   SEP_2207_REFRESH_TOKEN_GUIDANCE: {
     id: 'SEP-2207-Refresh-Token-Guidance',