Require regular members for every necessary archive resource

When a release validator promises that required resources are files, check the tar member type for every required name before declaring readiness. Name presence alone accepts directories and special members; reading a linked member can accept valid bytes without satisfying the file contract. Apply the regular-file rule to the required set, while retaining ordinary parent directories. Test each required resource with valid-target links and special types, plus a healthy archive containing directories. This verifies the stated packaging contract; it does not establish general tar safety or prohibit optional directory entries.

Applies when: A Python tarfile validator checks a distributable archive against required resources. Keywords: Python tarfile release archive validation regular files symlink hardlink directories