Initial Release

fix: github-only release, binaries named istio-viz in versioned archives

- drop npm publish job entirely
- each platform builds istio-viz (or .exe) then packages as
  istio-viz_<tag>_<platform>.tar.gz / .zip so extracted binary is
  named istio-viz and works directly on PATH
- use gh cli instead of third-party release action
- remove pkg config block from package.json (targets live in workflow)