feat(ui): add sticky version label to variables pane\n\n- Split left SplitView pane into scroll area + bottom bar\n- Show current app version from AssemblyInformationalVersion\n- Uses theme surface + top border per design tokens

src/AdvancedCalculator/ViewModels/MainViewModel.cs

@@ -6,6 +6,7 @@ using AdvancedCalculator.Models;
 using AdvancedCalculator.Services;
 using CSMic;
 using System;
+using System.Reflection;
 
 namespace AdvancedCalculator.ViewModels;
 
@@ -42,6 +43,12 @@ public partial class MainViewModel : ViewModelBase
     public ObservableCollection<HistoryItem> History { get; }
     public ObservableCollection<VariableItem> Variables { get; }
 
+    // App version string, sourced from AssemblyInformationalVersion
+    public string AppVersion { get; } =
+        typeof(MainViewModel).Assembly
+            .GetCustomAttribute<AssemblyInformationalVersionAttribute>()?
+            .InformationalVersion ?? "0.0.0";
+
     [RelayCommand]
     private void ToggleFunctions()
     {

src/AdvancedCalculator/Views/MainView.axaml

@@ -26,7 +26,8 @@
 
 		<!-- Left pane: Variables only (Functions moved to flyout) -->
 		<SplitView.Pane>
-			<Grid Background="{DynamicResource Brush.Surface}">
+			<Grid Background="{DynamicResource Brush.Surface}"
+			      RowDefinitions="*,Auto">
 
 				<!-- Variables list with empty-state hint overlay -->
 				<Grid Grid.Row="0">
@@ -64,6 +65,12 @@
 							   HorizontalAlignment="Center" VerticalAlignment="Center" />
 				</Grid>
 
+				<!-- Bottom sticky version bar -->
+				<Border Grid.Row="1" Padding="10" Background="{DynamicResource Brush.Surface}"
+				        BorderBrush="{DynamicResource Brush.Border}" BorderThickness="0,1,0,0">
+					<TextBlock Text="{Binding AppVersion, StringFormat='Version {0}'}"
+					           HorizontalAlignment="Left"/>
+				</Border>
 			</Grid>
 		</SplitView.Pane>