## Summary
- add a direct install script for macOS and Linux at
`scripts/install/install.sh`
- stage `install.sh` into `dist/` during release so it is published as a
GitHub release asset
- reuse the existing platform npm payload so the installer includes both
`codex` and `rg`
## Testing
- `bash -n scripts/install/install.sh`
- local macOS `curl | sh` smoke test against a locally served copy of
the script
