Verify Views files against decompiled, extract embedded types

Fixed files:
- SkiaImageButton.cs: Added SVG support with multi-path search
- SkiaNavigationPage.cs: Added LinuxApplication.IsGtkMode check
- SkiaRefreshView.cs: Added ICommand support (Command, CommandParameter)
- SkiaTemplatedView.cs: Added missing using statements

Extracted embedded types to separate files (matching decompiled pattern):
- From SkiaMenuBar.cs: MenuBarItem, MenuItem, SkiaMenuFlyout, MenuItemClickedEventArgs
- From SkiaNavigationPage.cs: NavigationEventArgs
- From SkiaTabbedPage.cs: TabItem
- From SkiaVisualStateManager.cs: SkiaVisualStateGroupList, SkiaVisualStateGroup, SkiaVisualState, SkiaVisualStateSetter
- From SkiaSwipeView.cs: SwipeItem, SwipeStartedEventArgs, SwipeEndedEventArgs
- From SkiaFlyoutPage.cs: FlyoutLayoutBehavior (already separate)
- From SkiaIndicatorView.cs: IndicatorShape (already separate)
- From SkiaBorder.cs: SkiaFrame
- From SkiaCarouselView.cs: PositionChangedEventArgs
- From SkiaCollectionView.cs: SkiaSelectionMode, ItemsLayoutOrientation
- From SkiaContentPresenter.cs: LayoutAlignment

Verified matching decompiled:
- SkiaContextMenu.cs, SkiaFlexLayout.cs, SkiaGraphicsView.cs

Build: 0 errors

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Rendering/RenderLayer.cs

@@ -0,0 +1,72 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using SkiaSharp;
+
+namespace Microsoft.Maui.Platform.Linux.Rendering;
+
+public class RenderLayer : IDisposable
+{
+    private SKBitmap? _bitmap;
+    private SKCanvas? _canvas;
+    private bool _isDirty = true;
+    private SKRect _bounds;
+    private bool _disposed;
+
+    public int ZIndex { get; }
+
+    public bool IsDirty => _isDirty;
+
+    public bool IsVisible { get; set; } = true;
+
+    public float Opacity { get; set; } = 1f;
+
+    public RenderLayer(int zIndex)
+    {
+        ZIndex = zIndex;
+    }
+
+    public SKCanvas BeginDraw(SKRect bounds)
+    {
+        if (_bitmap == null || _bounds != bounds)
+        {
+            _bitmap?.Dispose();
+            _canvas?.Dispose();
+
+            var width = Math.Max(1, (int)bounds.Width);
+            var height = Math.Max(1, (int)bounds.Height);
+            _bitmap = new SKBitmap(width, height, SKColorType.Bgra8888, SKAlphaType.Premul);
+            _canvas = new SKCanvas(_bitmap);
+            _bounds = bounds;
+        }
+
+        _canvas!.Clear(SKColors.Transparent);
+        _isDirty = false;
+        return _canvas;
+    }
+
+    public void Invalidate()
+    {
+        _isDirty = true;
+    }
+
+    public void DrawTo(SKCanvas canvas, SKRect bounds)
+    {
+        if (!IsVisible || _bitmap == null) return;
+
+        using var paint = new SKPaint
+        {
+            Color = SKColors.White.WithAlpha((byte)(Opacity * 255f))
+        };
+        canvas.DrawBitmap(_bitmap, bounds.Left, bounds.Top, paint);
+    }
+
+    public void Dispose()
+    {
+        if (_disposed) return;
+        _disposed = true;
+
+        _canvas?.Dispose();
+        _bitmap?.Dispose();
+    }
+}