X_REGISTRY_UNREACHABLE
Means
the registry did not answer — timeout, non-2xx, or a 200 that is not a packument
Typical cause
a rate limit or a network fault. Deliberately not reported as absent: a request that failed is not evidence that a package is unpublished, and treating it as one would send someone to re-bootstrap a live package
Fix
curl -sS -o /dev/null -w '%{http_code}\n' https://registry.npmjs.org/<pkg>, then re-run bun run scripts/registry-audit.ts --json