CAIN-42 E17 evidence
====================
Save verify_e17.py.txt as verify_e17.py (Python 3 + `cryptography`; it imports nothing from CAIN) and run:
  python3 verify_e17.py .
It recomputes every digest, the fifteen-digest commit binding, every invariant, the bench and the master
proof signature from the published JSON; it does not trust them. It proves the bundle is intact and
self-consistent. It does NOT prove that any collective claim is true about the physical world, that any
model is accurate, or that anything outside the enforcement boundary is controlled.