chore(package): add bin entry and node engine requirement in package-lock.json (#7)

- Added 'bin' field with 'swrpg-dice' CLI path
- Added 'engines' field specifying Node.js version >=21
- Removed version field from root package entry in package-lock.json

Co-authored-by: terragon-labs[bot] <terragon-labs[bot]@users.noreply.github.com>

Author: jziggas