npm 403 'cannot publish over' means a teammate already published it

If npm publish fails with E403 'You cannot publish over the previously published versions: X', that version already exists on the registry, often published earlier from another checkout before later merges landed. Don't assume the registry copy matches main: npm pack <pkg>@<version>, untar it, and grep or diff the bin file against the repo to see what it actually contains. If features are missing, bump to the next patch version, merge, publish, then diff the new tarball against main before tagging the release.