Captures the proposed requirements.txt -> cached virtualenv approach (keyed by
hash, --system-site-packages, QUARTO_PYTHON), its guard rails (auth gating,
egress restriction, resource caps) given anonymous write is enabled, lifecycle
(eviction, failure UX), a phased rollout, and the open decisions.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>