C.A.T.S. and Box — contract reference

The authoritative engine/setting contract lives in Notion.

Current CATS rules, design information, and book material are maintained in the CATS Notion Workbook. CATS Git owns software, websites, calculations, and builds. Google Drive holds references and finished editions. This file contains no independent contract.

This pointer is mirrored at CATS/docs/13-setting-repository.md and Box/docs/relationship-to-cats.md. Update both when the destination changes.