chore: migrate to MCP TypeScript SDK v2

[mattzcarey]

Summary

• Replace @modelcontextprotocol/sdk with @modelcontextprotocol/server v2 alpha.
• Update MCP server and Web Standard Streamable HTTP transport imports to the v2 package.
• Wrap tool inputSchema definitions with z.object(...) for the v2 Standard Schema API.
• Manually fix the dynamic non-codemode inputSchema case that the codemod missed.
• Add @cfworker/json-schema explicitly for the current @modelcontextprotocol/server@2.0.0-alpha.2 Workers validator dependency.
• Add MIGRATION_TRACKER.md with the commands run, manual fixes, validation, and upstream codemod follow-ups.

Validation

npm run typecheck
npm test
npm run deploy

Results:

• npm run typecheck: passed.
• npm test: passed, 178 tests.
• npm run deploy: deployed to staging.

Staging deploy:

Worker: cloudflare-api-mcp-staging
URL: https://staging.mcp.cloudflare.com
Version ID: f91b375b-d7ea-482d-8a10-d49e7e9dae43

Notes

• The dynamic inputSchema codemod miss was reported upstream on feat: add v2 codemod draft modelcontextprotocol/typescript-sdk#1950.
• @cfworker/json-schema is added manually for the current SDK alpha. If a later SDK release bundles runtime-selected validator defaults, this direct dependency can be removed.
• Tests still emit the existing vitest-pool-workers / CIMD global-scope logging noise, but the run passes.