The sandbox was declared "proven faithful" using the fidelity check BEFORE it was
hardened -- i.e. under the version that could false-green. That verdict must be
re-established under the hardened check before C2 feeds the carve upstream. Needs
the operator-held sandbox token; folds into the C2 step.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>