Sloth-ninja closes the loop on firm AI controls and deletion governance

The completed work gives firms tighter control over which chat models can be used, with the server enforcing the permitted choice rather than trusting the browser. It also adds deletion governance and reverses the default failure behaviour so the safer outcome applies when something goes wrong.

Both changes were deployed on 28 July. Production still needs the accompanying database update before the new firm-level preferences and deletion controls are fully available; until then, the system is designed to tolerate the missing database fields.