Adds a `residential_module_enabled` port setting (default ON) that
hides/disables the entire Residential surface when an admin turns it
off, mirroring the Tenancies / Invoices / Expenses module-toggle
pattern. Disabling is a soft hide — residential clients/interests are
preserved and reappear on re-enable.
Surfaces gated:
- Route guard: new residential/layout.tsx renders ModuleDisabledPage
(covers all 5 residential pages)
- Sidebar "Residential" section + mobile more-sheet tile (SSR-resolved
residentialModuleByPort threaded layout → app-shell → sidebar)
- Global search: residential client/interest buckets early-return at
the shared chokepoint so disabled-port records don't dead-end
- Public intake: /api/public/residential-inquiries 404s when off
- Admin Switch in settings-manager (writes via settings PUT)
Service TDD'd (residential-module.test.ts, 6 tests) plus a
disabled-port rejection test on the public endpoint. tsc + lint clean.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>