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

.prettierignore

@@ -3,3 +3,7 @@
 # repo's `prettier --check .` would reformat the file and fight the generator's
 # output (and the refresh workflow's `git diff` check).
 src/seps/traceability.json
+
+# Local tooling workspaces (not part of the repo).
+.claude/
+.sdk-under-test/