Two-layer protection on MasterResource and UserResource:
1. Form validation via ->rules() with Rule::unique() scoped to company_id
(prevents DB hit in normal flow, shows inline field error)
2. handleRecordCreation/handleRecordUpdate catches
UniqueConstraintViolationException as fallback — shows a Filament
danger notification and halts without showing an error page
Also adds phone uniqueness validation (scoped per tenant).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Vasyka
f1afcafa5d