Publish Yield Python packages on PyPI

[bigboateng]

Summary

• publish the Python SDK and six platform wheels to public PyPI with GitHub OIDC
• build npm and PyPI packages from one immutable source artifact
• finalize a release only after both registries match the expected package hashes
• document and test the public Python install path

Verification

• npm run test:release
• node scripts/check-release-control.mjs
• live repository control audit
• Python unit tests
• Go vet, test, and build
• TypeScript test and build
• Rust tests
• built and inspected all six wheels
• installed the macOS arm64 wheel and ran yskill --version