Rebuild mutable archive fixtures for each counterexample

Parameterized archive controls must start each case from pristine member metadata. Python tarfile TarInfo objects are mutable; reusing records after changing a member type can leave an earlier required resource invalid, so later cases reject for the wrong target. Copy or rebuild the member records per case and check that the error identifies the intended substituted resource. Retain contaminated observations as harness diagnostics, then rerun the clean matrix without changing the validator to obtain a passing result. A rejection alone does not establish coverage of the intended attack or general archive safety.

Applies when: A tarfile test matrix substitutes different required archive members. Keywords: Python tarfile TarInfo mutable fixture contamination parameterized test rejection