refactored data providers with centralized cache resolution, unified UI using custom dialogs and bottom sheets, and enhanced network error handling for Dio and TLS errors

lib/widget/file_viewer.dart

@@ -81,7 +81,7 @@ class _DeferredPdfViewerState extends State<_DeferredPdfViewer> {
 }
 
 class _FileViewerState extends State<FileViewer> {
-  PhotoViewController photoViewController = PhotoViewController();
+  final PhotoViewController photoViewController = PhotoViewController();
 
   late SettingsCubit settings = context.read<SettingsCubit>();
   late bool openExternal;
@@ -92,6 +92,12 @@ class _FileViewerState extends State<FileViewer> {
     super.initState();
   }
 
+  @override
+  void dispose() {
+    photoViewController.dispose();
+    super.dispose();
+  }
+
   @override
   Widget build(BuildContext context) {
     AppBar appbar({List<Widget> actions = const []}) => AppBar(
@@ -195,10 +201,8 @@ class _FileViewerState extends State<FileViewer> {
         OpenFilex.open(widget.path).then((result) {
           if (!context.mounted) return;
           Navigator.of(context).pop();
-          if(result.type != ResultType.done) {
-            showDialog(context: context, builder: (context) => AlertDialog(
-                content: Text(result.message),
-              ));
+          if (result.type != ResultType.done) {
+            InfoDialog.show(context, result.message);
           }
         });