fix(text): show selected formatting and style controls

Use category-filtered font and selected-item dropdowns, separate horizontal and vertical alignment, and reuse the border-color palette templates for text color. Persist vertical alignment additively. Follow the established static text-source pattern: https://obsproject.com/kb/text-sources

ViewModels/MainViewModel.cs

@@ -74,6 +74,7 @@ public partial class MainViewModel : ViewModelBase
                 OnPropertyChanged(nameof(IsBlurSelected));
                 OnPropertyChanged(nameof(IsElementsPanelEmpty));
                 OnPropertyChanged(nameof(CanToggleClipShape));
+                SyncTextFontCategory();
                 if (_selectedElement != null)
                     _selectedElement.PropertyChanged += OnSelectedElementPropertyChanged;
             }
@@ -113,6 +114,17 @@ public partial class MainViewModel : ViewModelBase
         // property. Cheap: the bake is recomputed on demand, once.
         if (StagedScene != null) _sceneGraph.InvalidateBake(StagedScene);
 
+        if (sender is Source text && text.Type == SourceType.TextOverlay)
+        {
+            if (e.PropertyName == nameof(Source.TextFontFamily))
+            {
+                SelectedTextFontType = FontTypeFor(text.TextFontFamily);
+                OnPropertyChanged(nameof(SelectedTextFontFamily));
+            }
+            if (e.PropertyName == nameof(Source.TextFontSize))
+                OnPropertyChanged(nameof(TextFontSizeOptions));
+        }
+
         if (e.PropertyName == nameof(SceneElement.UseDefaultBackground))
         {
             // ⛔ Turning the default back ON has to RE-STAMP the shipped art. Browse… writes the