CAIN-42 E18 evidence
====================
Save verify_e18.py.txt as verify_e18.py (Python 3 + `cryptography`; it imports nothing from CAIN) and run:
  python3 verify_e18.py .
It recomputes every digest and the sixteen-digest spatial commit binding, re-derives that the committed
action's policy/actionability/risk/uncertainty/authority verdicts permit it, checks the invariant and bench
records for consistency (it does not re-run them), and checks the
master proof signature from the published JSON. It proves the bundle is intact and
self-consistent. It does NOT prove that any spatial claim is true about the physical world, that any model is
accurate, or that any vehicle, drone or robot is safe or controlled.