fix: side-by-side diff scroll desync on hidden-tab rebuild and tab switch (#2611)

Author: JC-Chung

src/Views/TextDiffView.axaml.cs

@@ -1014,6 +1014,8 @@ protected override void OnLoaded(RoutedEventArgs e)
         {
             base.OnLoaded(e);
 
+            ApplyTemplate();
+
             _scrollViewer = this.FindDescendantOfType<ScrollViewer>();
             if (_scrollViewer != null)
             {
@@ -1199,6 +1201,8 @@ protected override void OnLoaded(RoutedEventArgs e)
         {
             base.OnLoaded(e);
 
+            ApplyTemplate();
+
             _scrollViewer = this.FindDescendantOfType<ScrollViewer>();
             if (_scrollViewer != null)
             {