Gate finding (quality, Low): the nested seeds covered only .ssh, .aws and
.envrc, so removing .gnupg or .kube from the any-depth _EXPORT_CREDENTIAL_FILES
list left every test green (root copies are still caught by
PROFILE_CREDENTIAL_PATHS). Seed skills/s/.gnupg/x and skills/s/.kube/config too;
dropping .gnupg from the any-depth list now fails the export invariant.