fix: resolve directory path access and add existence check before caching gifs in home bloc

lib/features/home/presentation/bloc/home_bloc.dart

@@ -92,8 +92,9 @@ class HomeBloc extends Bloc<HomeEvent, HomeState> {
   Future<void> preCacheQuestionGifs() async {
     try {
       final Directory directory = Directory(
-        '${StoragePath.documentDir}/question_image',
+        '${StoragePath.documentDir.path}/question_image',
       );
+      if (!directory.existsSync()) return;
       final List<FileSystemEntity> files = directory.listSync();
       await Future.wait(
         files.map(
@@ -110,8 +111,9 @@ class HomeBloc extends Bloc<HomeEvent, HomeState> {
   Future<void> preCacheAnswerGifs() async {
     try {
       final Directory directory = Directory(
-        '${StoragePath.documentDir}/answer_image',
+        '${StoragePath.documentDir.path}/answer_image',
       );
+      if (!directory.existsSync()) return;
       final List<FileSystemEntity> files = directory.listSync();
       await Future.wait(
         files.map(