Update local backups availability during rollout

Co-authored-by: trevor-signal <131492920+trevor-signal@users.noreply.github.com>

ts/background.preload.ts

@@ -271,7 +271,7 @@ import { MessageModel } from './models/messages.preload.js';
 import { waitForEvent } from './shims/events.dom.js';
 import { sendSyncRequests } from './textsecure/syncRequests.preload.js';
 import { handleServerAlerts } from './util/handleServerAlerts.preload.js';
-import { isLocalBackupsEnabled } from './util/isLocalBackupsEnabled.dom.js';
+import { isLocalBackupsEnabled } from './util/isLocalBackupsEnabled.preload.js';
 import { NavTab, SettingsPage, ProfileEditorPage } from './types/Nav.std.js';
 import { initialize as initializeDonationService } from './services/donations.preload.js';
 import { MessageRequestResponseSource } from './types/MessageRequestResponseEvent.std.js';

ts/services/backups/index.preload.ts

@@ -83,7 +83,7 @@ import {
 import { FileStream } from './util/FileStream.node.js';
 import { ToastType } from '../../types/Toast.dom.js';
 import { isAdhoc, isNightly } from '../../util/version.std.js';
-import { isLocalBackupsEnabled } from '../../util/isLocalBackupsEnabled.dom.js';
+import { isLocalBackupsEnabled } from '../../util/isLocalBackupsEnabled.preload.js';
 import type { ValidateLocalBackupStructureResultType } from './util/localBackup.node.js';
 import {
   writeLocalBackupMetadata,

ts/state/smart/Preferences.preload.tsx

@@ -117,6 +117,7 @@ import type { SmartPreferencesEditChatFolderPageProps } from './PreferencesEditC
 import type { ExternalProps as SmartNotificationProfilesProps } from './PreferencesNotificationProfiles.preload.js';
 import { useMegaphonesActions } from '../ducks/megaphones.preload.js';
 import type { ZoomFactorType } from '../../types/StorageKeys.std.js';
+import { isLocalBackupsEnabled } from '../../util/isLocalBackupsEnabled.preload.js';
 
 const DEFAULT_NOTIFICATION_SETTING = 'message';
 
@@ -578,9 +579,7 @@ export function SmartPreferences(): React.JSX.Element | null {
     Settings.isContentProtectionSupported(OS);
   const isContentProtectionNeeded = Settings.isContentProtectionNeeded(OS);
 
-  const backupLocalBackupsEnabled = isFeaturedEnabledSelector({
-    betaKey: 'desktop.localBackups.beta',
-    prodKey: 'desktop.localBackups.prod',
+  const backupLocalBackupsEnabled = isLocalBackupsEnabled({
     currentVersion: version,
     remoteConfig: items.remoteConfig,
   });

ts/util/isLocalBackupsEnabled.dom.ts

@@ -1,11 +0,0 @@
-// Copyright 2025 Signal Messenger, LLC
-// SPDX-License-Identifier: AGPL-3.0-only
-
-import { isFeaturedEnabledNoRedux } from './isFeatureEnabled.dom.js';
-
-export function isLocalBackupsEnabled(): boolean {
-  return isFeaturedEnabledNoRedux({
-    betaKey: 'desktop.localBackups.beta',
-    prodKey: 'desktop.localBackups.prod',
-  });
-}

ts/util/isLocalBackupsEnabled.preload.ts

@@ -0,0 +1,44 @@
+// Copyright 2025 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import type { ReadonlyObjectDeep } from 'type-fest/source/readonly-deep.js';
+import { isEnabled, type ConfigMapType } from '../RemoteConfig.dom.js';
+import {
+  isFeaturedEnabledNoRedux,
+  isFeaturedEnabledSelector,
+} from './isFeatureEnabled.dom.js';
+import { itemStorage } from '../textsecure/Storage.preload.js';
+import { isNightly } from './version.std.js';
+import { isTestOrMockEnvironment } from '../environment.std.js';
+
+const IOS_USER_AGENT = 'OWI';
+
+export function isLocalBackupsEnabled(reduxArgs?: {
+  currentVersion: string;
+  remoteConfig: ReadonlyObjectDeep<ConfigMapType> | undefined;
+}): boolean {
+  // This is a temporary guard until iOS supports importing local backups
+  // Android no longer sends its OWA agent string, so we have to rely on iOS
+  if (
+    itemStorage.get('userAgent') === IOS_USER_AGENT &&
+    !isNightly(window.getVersion()) &&
+    !isTestOrMockEnvironment() &&
+    !isEnabled('desktop.internalUser', reduxArgs?.remoteConfig)
+  ) {
+    return false;
+  }
+
+  if (reduxArgs) {
+    return isFeaturedEnabledSelector({
+      currentVersion: reduxArgs.currentVersion,
+      remoteConfig: reduxArgs.remoteConfig,
+      betaKey: 'desktop.localBackups.beta',
+      prodKey: 'desktop.localBackups.prod',
+    });
+  }
+
+  return isFeaturedEnabledNoRedux({
+    betaKey: 'desktop.localBackups.beta',
+    prodKey: 'desktop.localBackups.prod',
+  });
+}