implemented a comprehensive Nextcloud file sharing system with support for user, group, and public link shares with gating based on server-side permissions; added sharing management interfaces including a share sheet; updated the file list with visual badges for incoming shares and improved OCS API response handling.

lib/routing/app_routes.dart

@@ -15,6 +15,7 @@ import '../state/app/modules/chat/bloc/chat_bloc.dart';
 import '../state/app/modules/chat_list/bloc/chat_list_bloc.dart';
 import '../state/app/modules/marianum_message/bloc/marianum_message_state.dart';
 import '../view/pages/files/files.dart';
+import '../view/pages/files/sharing/sharee_picker_page.dart';
 import '../view/pages/foreign_timetable/element_picker_page.dart';
 import '../view/pages/marianum_message/marianum_message_view.dart';
 import '../view/pages/more/feedback/feedback_dialog.dart';
@@ -91,6 +92,27 @@ class AppRoutes {
     return result as TimetableElementRef?;
   }
 
+  /// Opens the user/group picker for sharing a file and resolves to the chosen
+  /// recipient (or null if dismissed). Which kinds are offered is gated by the
+  /// Nextcloud sharing capabilities at the call site.
+  static Future<ShareeRef?> openShareePicker(
+    BuildContext context, {
+    required bool allowUsers,
+    required bool allowGroups,
+  }) async {
+    // Push untyped (T = dynamic) and cast the popped result ourselves —
+    // pushScreen can't carry a concrete non-Widget T (see openElementPicker).
+    final result = await pushScreen(
+      context,
+      withNavBar: false,
+      screen: ShareePickerPage(
+        allowUsers: allowUsers,
+        allowGroups: allowGroups,
+      ),
+    );
+    return result as ShareeRef?;
+  }
+
   static void openMarianumMessage(
     BuildContext context,
     String basePath,