fix(mobile-history): drop history cache writes that outlive the auth scope

apps/mobile-rn/App.tsx

@@ -61,7 +61,8 @@ import type { NotificationNavigationTarget } from './src/features/notifications/
 import { loadPendingInviteToken } from './src/features/teams/pending-invite'
 import { listTeams } from './src/features/teams/team-service'
 import { listHistoryPage } from './src/features/history/history-service'
-import { saveHistoryCache } from './src/features/history/history-cache'
+import { createHistoryCacheScope } from './src/features/history/history-cache-writer'
+import { synchronizeAfterMissedNotifications } from './src/features/notifications/missed-notification-sync'
 import { useRecordingProcessingQueue } from './src/features/recording/use-recording-processing-queue'
 import {
   getPendingIncomingMediaId,
@@ -246,22 +247,22 @@ function RootNavigator(): React.ReactElement {
     void routeIncomingMedia()
   }, [routeIncomingMedia])
 
+  // Invalidated whenever the signed-in user changes (including the null that
+  // the logout privacy purge publishes) so an in-flight full sync cannot write
+  // the previous account's history cache back after the purge.
+  const [historyCacheScope] = useState(createHistoryCacheScope)
+  useEffect(() => () => historyCacheScope.invalidate(), [historyCacheScope, user?.id])
+
   const synchronizeMissedNotifications = useCallback(async (): Promise<boolean> => {
     const userId = user?.id
     if (!userId) return false
-    try {
-      const [history] = await Promise.all([
-        listHistoryPage({ userId, filter: 'all', pageSize: 50 }),
-        listTeams(userId),
-        fetchEntitlementSnapshot(userId),
-      ])
-      await saveHistoryCache(userId, history.entries)
-      await entitlement.refresh()
-      return true
-    } catch {
-      return false
-    }
-  }, [entitlement, user?.id])
+    return synchronizeAfterMissedNotifications(userId, historyCacheScope.capture(), {
+      listRecentHistory: (id) => listHistoryPage({ userId: id, filter: 'all', pageSize: 50 }),
+      listTeams,
+      fetchEntitlement: fetchEntitlementSnapshot,
+      refreshEntitlement: () => entitlement.refresh(),
+    })
+  }, [entitlement, historyCacheScope, user?.id])
 
   useNotificationRuntime({
     navigate: navigateFromNotification,