v0.2.0

fix: binary build infrastructure and release hardening (#1)

- Fix TLS path: ../tls → ../tls_pure in pixi.toml, build_and_run.sh, and CI workflows
- Add build-and-smoke CI job to test.yml (builds binary + smoke tests on every PR)
- Add SHA256 checksum to release artifacts in release.yml
- Add scripts/install.sh for curl-pipe installation
- Add test-build pixi task for local binary smoke testing
- Update README with quick-install and manual install instructions

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>