ci: add canonical hypatia-scan.yml (missing — estate uniformity) (#26)

This repo had no hypatia-scan.yml; adding the canonical 413-line
workflow so it carries the estate security scan like all other repos.
hyperpolymath/standards#87.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: hyperpolymath