fix(core): cover optional spec schema properties

[rechedev9]

Fixes #1298

Summary

• add a recursive spec-vs-schema coverage test that fails when named optional spec properties are missing from SDK object schemas
• fill the current gaps the new check exposes in core schemas (PromptArgument.title, PromptReference.title, tool $schema fields, and elicitation requestedSchema.$schema)
• keep the existing mutual-assignability checks in place while extending coverage to the optional-property case that PR Add optional description field to Implementation schema #1295 slipped through

Verification

• ../../node_modules/.bin/tsgo -p tsconfig.json --noEmit
• ../../node_modules/.bin/eslint src/
• ../../node_modules/.bin/prettier --ignore-path ../../.prettierignore --check .
• corepack pnpm --filter @modelcontextprotocol/core test

[changeset-bot]

⚠️ No Changeset found

Latest commit: b3f33ba

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

[pkg-pr-new]

Open in StackBlitz

@modelcontextprotocol/client

npm i https://pkg.pr.new/modelcontextprotocol/typescript-sdk/@modelcontextprotocol/client@1798

@modelcontextprotocol/server

npm i https://pkg.pr.new/modelcontextprotocol/typescript-sdk/@modelcontextprotocol/server@1798

@modelcontextprotocol/express

npm i https://pkg.pr.new/modelcontextprotocol/typescript-sdk/@modelcontextprotocol/express@1798

@modelcontextprotocol/hono

npm i https://pkg.pr.new/modelcontextprotocol/typescript-sdk/@modelcontextprotocol/hono@1798

@modelcontextprotocol/node

npm i https://pkg.pr.new/modelcontextprotocol/typescript-sdk/@modelcontextprotocol/node@1798

commit: b3f33ba