Adds assertResidentialModuleEnabled(ctx.portId) as the first statement in every residential v1 handler (24 handlers across 13 files), mirroring the Tenancies pattern. Previously the disabled-module state was enforced only in the page layout, so a disabled module still accepted API writes (including partner-forward emails on residential interest creation). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>