fix(platform): mount the Settings leave guard on live data again

The live shell's SessionState mounted the discard dialog for live
Settings; consolidating the local preview removed it, so leaving a dirty
editor (such as a data retention pattern) no longer asked first. Fixture
Settings and the fixture integration center keep their own mounts.

Author: emir-karabeg

apps/sim/platform/app/(shell)/_components/session-state/session-state.tsx

@@ -1,6 +1,7 @@
 'use client'
 
 import styles from '@/platform/app/(shell)/_components/session-state/session-state.module.css'
+import { SettingsLeaveGuard } from '@/platform/app/(shell)/_components/session-state/settings-leave-guard'
 import { Button } from '@/platform/design-system/components'
 import { useImpersonation, useSessionRecovery } from '@/platform/lib/data/session'
 
@@ -43,6 +44,7 @@ export function SessionState() {
     <>
       <ImpersonationBanner />
       <SessionExpired />
+      <SettingsLeaveGuard />
     </>
   )
 }