* feat: support "draft" as a first-class spec version target
- Add LATEST_SPEC_VERSION and DATED_SPEC_VERSIONS constants so the next
spec release is a one-line change in types.ts.
- Accept "draft" as a valid protocolVersion in the initialize check and
mock-server response.
- --spec-version draft now selects latest-dated scenarios plus draft-tagged
ones, so SEP authors can run the full suite against an SDK tracking the
in-progress spec without retagging core scenarios.
- Forward --spec-version to the client process via
MCP_CONFORMANCE_SPEC_VERSION so SDK examples can pick the matching
protocolVersion.
Closes#253
* review: collapse SpecVersion to wire strings; dedup NEGOTIABLE_PROTOCOL_VERSIONS; split out 'extension'
Addresses review feedback from @felixweinberger and @mikekistler:
- SpecVersion is now always a wire protocolVersion string
(DatedSpecVersion | typeof DRAFT_PROTOCOL_VERSION). The separate
'draft' tag literal is gone from the type system; 'draft' survives
only as a CLI input alias in resolveSpecVersion. Removes the
tag-vs-wire confusion and the specVersionToProtocolVersion mapping.
- NEGOTIABLE_PROTOCOL_VERSIONS in types.ts is the single source for
what the mock server accepts on initialize (was duplicated in
checks/client.ts and scenarios/client/initialize.ts).
- 'extension' moved out of SpecVersion into a separate ScenarioSpecTag
type. --spec-version extension is no longer valid; extension scenarios
remain reachable via --suite extensions.
- Draft-tagged scenarios now use the DRAFT_PROTOCOL_VERSION constant
so a draft revision bump is a one-line change in types.ts.
17f1f93cc0