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

Services/TextOverlayRenderer.cs

@@ -59,6 +59,7 @@ public sealed class TextOverlayRenderer
         source.TextItalic,
         source.TextUnderline,
         source.TextAlignment,
+        source.TextVerticalAlignment,
         RasterDimension(source.Width),
         RasterDimension(source.Height));
 
@@ -100,7 +101,13 @@ public sealed class TextOverlayRenderer
             };
             if (config.Underline)
                 formatted.SetTextDecorations(TextDecorations.Underline, 0, config.Content.Length);
-            drawing.DrawText(formatted, new Point(0, 0));
+            var top = config.VerticalAlignment switch
+            {
+                TextLayerVerticalAlignment.Center => Math.Max(0, (config.Height - formatted.Height) / 2),
+                TextLayerVerticalAlignment.Bottom => Math.Max(0, config.Height - formatted.Height),
+                _ => 0,
+            };
+            drawing.DrawText(formatted, new Point(0, top));
         }
 
         var bitmap = new RenderTargetBitmap(config.Width, config.Height, 96, 96, PixelFormats.Pbgra32);
@@ -145,6 +152,7 @@ public sealed class TextOverlayRenderer
         bool Italic,
         bool Underline,
         TextLayerAlignment Alignment,
+        TextLayerVerticalAlignment VerticalAlignment,
         int Width,
         int Height);
 }