Explain why the service-layer + tenancy-first API made Phase-3 module scoping nearly free Adds a "Rolling isolation to the other modules (Phase 3)" section to the isolation page (per-module recipe + why the earlier refactors paid off + the honest caveat about perimeter reads), and cross-links it from the service-layer architecture page's company-scope section + Related.
Add Multi-Tenancy-Isolation page: isolation model + the three-sweep hardening audit