fix(account): 本地化网络异常文案

lib/pages/account/account_devices_logic.dart

@@ -24,9 +24,7 @@ class AccountDevicesLogic extends ChangeNotifier {
     try {
       devices = await _repository.devices();
     } catch (failure) {
-      error = failure is ApiException
-          ? failure.message
-          : 'accountDevicesLoadFailed';
+      error = failure is ApiException ? failure.message : 'networkError';
     } finally {
       loading = false;
       _notify();

lib/pages/account/account_export_logic.dart

@@ -25,9 +25,7 @@ class AccountExportLogic extends ChangeNotifier {
     try {
       data = await _repository.export();
     } catch (failure) {
-      error = failure is ApiException
-          ? failure.message
-          : 'accountExportLoadFailed';
+      error = failure is ApiException ? failure.message : 'networkError';
     } finally {
       loading = false;
       _notify();

lib/pages/account/account_profile_logic.dart

@@ -30,7 +30,7 @@ class AccountProfileLogic extends ChangeNotifier {
     try {
       profile = await _repository.profile();
     } catch (failure) {
-      error = _message(failure) ?? 'accountProfileLoadFailed';
+      error = _message(failure);
     } finally {
       loading = false;
       _notify();
@@ -68,7 +68,7 @@ class AccountProfileLogic extends ChangeNotifier {
       await onProfileUpdated(next);
       return true;
     } catch (failure) {
-      error = _message(failure) ?? 'accountProfileSaveFailed';
+      error = _message(failure);
       return false;
     } finally {
       saving = false;
@@ -76,8 +76,8 @@ class AccountProfileLogic extends ChangeNotifier {
     }
   }
 
-  String? _message(Object failure) =>
-      failure is ApiException ? failure.message : null;
+  String _message(Object failure) =>
+      failure is ApiException ? failure.message : 'networkError';
 
   void _notify() {
     if (!_disposed) notifyListeners();