False-assurance principle: my v9 PASS (@1c34e3cb) is overtaken by the stricter B9 no-site bar after homelab's 4th-round FAIL (no -S → system-site .pth exec + sitecustomize run unpinned code at child startup). NOT fire-authorization; v10 no-site fix incoming. Authored by ms-secrev-828 reviewer lane (my own artifact). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>