build(ts-sdk): prepare 0.2.1 release

[SeaOceanO]

Summary

• prepare @awiki/anp-typescript-sdk@0.2.1 from the APIs already present on master
• verify the packed ESM build exposes all 10 APIs required by AWiki Lite
• make the SDK clean command and Python example test portable to Windows
• document the POSIX mode versus Windows ACL behavior for plaintext identity state

The published npm package @awiki/anp-typescript-sdk@0.2.0 predates commit a9ef02d and is missing all 10 Lite-required exports: DeviceManifestEntry, six profile constants, buildVnextDidDocument, generateRfc9421OriginProof, and validateDeviceManifest. The implementations already exist in the official repository; this PR prepares a patch release and adds a compiled-package gate so a future package cannot silently omit them.

Verification

• npm run typecheck
• npm test: 92 passed
• npm run build
• npm run check:dist: verified 10 Lite SDK exports
• npm pack: produced @awiki/anp-typescript-sdk@0.2.1
• installed the tarball into an isolated AWiki Lite checkout: typecheck and build passed; 36 TypeScript Lite tests passed (the old checkout's POSIX-only fcntl lock test was excluded on Windows)
• clean consumer TypeScript import and Node runtime export checks passed with all 10 exports resolved
• changed-file Prettier check and git diff --check passed

This PR does not publish to npm. Publishing 0.2.1 remains a maintainer action after review and merge.