Enable document history (undo/redo)

src/frontend/lib/providers/note_editor_provider.dart

@@ -1333,6 +1333,16 @@ class NoteEditorProvider with ChangeNotifier implements NoteEditorViewModel {
     return blockId;
   }
 
+  @override
+  void redo() {
+    _documentBuilder.redo();
+  }
+
+  @override
+  void undo() {
+    _documentBuilder.undo();
+  }
+
   @override
   void resetState() {
     _logger.info('Resetting NoteEditorProvider state');

src/frontend/lib/screens/note_editor_screen.dart

@@ -212,11 +212,20 @@ class _NoteEditorScreenState extends State<NoteEditorScreen> {
   @override
   Widget build(BuildContext context) {
     return Scaffold(
-      // Add AppBarCommon with ONLY theme switching functionality
       appBar: AppBarCommon(
-        title: '', // Empty title as we have our own title field
-        showBackButton: false, // No back button in app bar
+        title: '',
+        showBackButton: true,
         actions: [
+          IconButton(
+            icon: const Icon(Icons.undo_outlined),
+            tooltip: 'Undo last edit',
+            onPressed: () => _noteEditorViewModel.undo(),
+          ),
+          IconButton(
+            icon: const Icon(Icons.redo_outlined),
+            tooltip: 'Redo last edit',
+            onPressed: () => _noteEditorViewModel.redo(),
+          ),
           IconButton(
             icon: const Icon(Icons.refresh_outlined),
             tooltip: 'Refresh note content',

src/frontend/lib/screens/user_profile_screen.dart

@@ -16,7 +16,6 @@ class UserProfileScreen extends StatefulWidget {
 
 class _UserProfileScreenState extends State<UserProfileScreen> {
   final Logger _logger = Logger('UserProfileScreen');
-  final GlobalKey<ScaffoldState> _scaffoldKey = GlobalKey<ScaffoldState>();
   final _formKey = GlobalKey<FormState>();
   final _passwordFormKey = GlobalKey<FormState>();
 
@@ -176,12 +175,10 @@ class _UserProfileScreenState extends State<UserProfileScreen> {
     final theme = Theme.of(context);
 
     return Scaffold(
-      key: _scaffoldKey,
       appBar: AppBarCommon(
         title: 'Profile',
         onBackPressed: () => context.go('/'),
         showBackButton: true,
-        onMenuPressed: () => _scaffoldKey.currentState?.openDrawer(),
         actions: const [ThemeSwitcher()],
       ),
       drawer: const SidebarDrawer(),

src/frontend/lib/utils/document_builder.dart

@@ -96,8 +96,11 @@ class DocumentBuilder {
     _composer.selectionNotifier.addListener(_updateToolbarDisplay);
 
     // Create editor with our document and composer
-    _editor =
-        createDefaultDocumentEditor(document: _document, composer: _composer);
+    _editor = createDefaultDocumentEditor(
+      document: _document,
+      composer: _composer,
+      isHistoryEnabled: true,
+    );
 
     // Add action tags listener for inline commands
     _inlineCommandsPlugin = ActionTagsPlugin();
@@ -1318,6 +1321,14 @@ class DocumentBuilder {
     return document;
   }
 
+  void redo() {
+    _editor.redo();
+  }
+
+  void undo() {
+    _editor.undo();
+  }
+
   // Create Super Editor with configured components for SuperEditor 0.3.0
   Widget createSuperEditor({
     required bool readOnly,

src/frontend/lib/viewmodel/note_editor_viewmodel.dart

@@ -67,6 +67,9 @@ abstract class NoteEditorViewModel extends BaseViewModel {
   void setFocusToBlock(String blockId);
   String? consumeFocusRequest();
 
+  void redo() {}
+  void undo() {}
+
   // User modified blocks tracking
   Set<String> get userModifiedBlockIds;
 

src/frontend/lib/widgets/app_bar_common.dart

@@ -4,7 +4,6 @@ import 'package:go_router/go_router.dart';
 class AppBarCommon extends StatelessWidget implements PreferredSizeWidget {
   final String? title;
   final List<Widget>? actions;
-  final Widget? leading;
   final bool showBackButton;
   final VoidCallback? onBackPressed;
   final VoidCallback? onMenuPressed;
@@ -13,12 +12,12 @@ class AppBarCommon extends StatelessWidget implements PreferredSizeWidget {
   final Color? backgroundColor;
   final Color? foregroundColor;
   final bool showProfileButton;
-
+  final bool showUndoRedoButtons;
+
   const AppBarCommon({
     Key? key,
     this.title,
     this.actions,
-    this.leading,
     this.showBackButton = true,
     this.onBackPressed,
     this.onMenuPressed,
@@ -27,31 +26,31 @@ class AppBarCommon extends StatelessWidget implements PreferredSizeWidget {
     this.backgroundColor,
     this.foregroundColor,
     this.showProfileButton = true,
+    this.showUndoRedoButtons = false,
   }) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
-    Widget? leadingWidget = leading;
+    List<Widget>? leadingWidgets = [];
 
-    // If leading is not provided and showBackButton is true, show back button
-    if (leading == null) {
-      if (showBackButton) {
-        leadingWidget = IconButton(
-          icon: const Icon(Icons.arrow_back),
-          onPressed: onBackPressed ?? () => Navigator.of(context).pop(),
-        );
-      } else if (onMenuPressed != null) {
-        // Show menu button if onMenuPressed callback is provided
-        leadingWidget = IconButton(
-          icon: const Icon(Icons.menu),
-          onPressed: onMenuPressed,
-        );
-      }
+    if (onMenuPressed != null) {
+      // Show menu button if onMenuPressed callback is provided
+      leadingWidgets.add(IconButton(
+        icon: const Icon(Icons.menu),
+        onPressed: onMenuPressed,
+      ));
     }
 
+    if (showBackButton) {
+      leadingWidgets.add(IconButton(
+        icon: const Icon(Icons.arrow_back),
+        onPressed: onBackPressed ?? () => Navigator.of(context).pop(),
+      ));
+    } 
+
     // Create a copy of the actions list to modify if needed
     List<Widget>? actionWidgets = actions != null ? List<Widget>.from(actions!) : [];
-    
+
     // Add profile button to actions if showProfileButton is true
     if (showProfileButton) {
       actionWidgets.add(
@@ -67,13 +66,18 @@ class AppBarCommon extends StatelessWidget implements PreferredSizeWidget {
     }
 
     return AppBar(
+      leading: Builder(builder: (context) => Row(
+          mainAxisSize: MainAxisSize.min,
+          crossAxisAlignment: CrossAxisAlignment.stretch,
+          children: leadingWidgets,
+        ),
+      ),
+      actions: actionWidgets,
       title: title != null ? Text(title!) : null,
       centerTitle: centerTitle,
       elevation: elevation,
       backgroundColor: backgroundColor,
       foregroundColor: foregroundColor,
-      leading: leadingWidget,
-      actions: actionWidgets,
     );
   }