fix(cli): derive reported version from package manifest

[bhavanikalisetty]

Summary

• patch the release to 0.2.3 because npm package 0.2.2 still reports executable version 0.2.1
• derive rtrvr --version from the package manifest instead of a hardcoded string
• add a built-artifact test so manifest and executable versions cannot drift again

Verification

• Node 20.20 and Node 22.10: build, typecheck, and all 25 tests pass
• executable reports 0.2.3
• packed tarball contains package.json, README, dist/index.js, and dist/index.d.ts