added a swipeable media gallery for chat and folder images and videos with server previews, on-demand originals and zoom, and marked document previews in chat so they no longer pass for photos

lib/model/session_wipe.dart

@@ -18,6 +18,7 @@ import '../share_intent/share_intent_listener.dart';
 import '../utils/app_paths.dart';
 import '../utils/downloads/download_manager.dart';
 import '../utils/file_clipboard.dart';
+import '../widget/media_gallery/gallery_cache.dart';
 import '../widget_data/widget_sync.dart';
 
 /// Removes what an account leaves on the device outside its own storage (see
@@ -55,6 +56,7 @@ abstract final class SessionWipe {
       final dir = await DownloadManager.downloadsDirectory();
       if (dir.existsSync()) await dir.delete(recursive: true);
     });
+    await _stepAsync('gallery originals', GalleryOriginals.instance.clear);
     await _stepAsync(
       'notification tray',
       NotificationService().flutterLocalNotificationsPlugin.cancelAll,