implemented background prefetching for files root, added 24-hour caching for root directory listing, and enabled cache renewal for manual refreshes

lib/state/app/modules/files/bloc/files_bloc.dart

@@ -37,7 +37,9 @@ class FilesBloc
   Future<void> refresh() async {
     add(RefetchStarted<FilesState>());
     final path = innerState?.currentPath ?? initialPath;
-    await _query(path);
+    // Explicit user action — bypass the cache TTL so the root listing also
+    // refetches even though it is otherwise cached for a day.
+    await _query(path, renew: true);
   }
 
   Future<void> setPath(List<String> path) async {
@@ -52,7 +54,7 @@ class FilesBloc
     await refresh();
   }
 
-  Future<void> _query(List<String> path) async {
+  Future<void> _query(List<String> path, {bool renew = false}) async {
     final pathString = path.isEmpty ? '/' : path.join('/');
 
     // Drop late results when [setPath] has navigated elsewhere or when the
@@ -71,6 +73,7 @@ class FilesBloc
     try {
       listing = await repo.data.listFiles(
         pathString,
+        renew: renew,
         onCacheData: (cached) {
           if (isStale()) return;
           // Cached payload arrives before the network call settles. Surface it