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/LayeredRenderer.cs

@@ -0,0 +1,75 @@
+// 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 LayeredRenderer : IDisposable
+{
+    private readonly Dictionary<int, RenderLayer> _layers = new();
+    private readonly object _lock = new();
+    private bool _disposed;
+
+    public RenderLayer GetLayer(int zIndex)
+    {
+        lock (_lock)
+        {
+            if (!_layers.TryGetValue(zIndex, out var layer))
+            {
+                layer = new RenderLayer(zIndex);
+                _layers[zIndex] = layer;
+            }
+            return layer;
+        }
+    }
+
+    public void RemoveLayer(int zIndex)
+    {
+        lock (_lock)
+        {
+            if (_layers.TryGetValue(zIndex, out var layer))
+            {
+                layer.Dispose();
+                _layers.Remove(zIndex);
+            }
+        }
+    }
+
+    public void Composite(SKCanvas canvas, SKRect bounds)
+    {
+        lock (_lock)
+        {
+            foreach (var layer in _layers.Values.OrderBy(l => l.ZIndex))
+            {
+                layer.DrawTo(canvas, bounds);
+            }
+        }
+    }
+
+    public void InvalidateAll()
+    {
+        lock (_lock)
+        {
+            foreach (var layer in _layers.Values)
+            {
+                layer.Invalidate();
+            }
+        }
+    }
+
+    public void Dispose()
+    {
+        if (_disposed) return;
+        _disposed = true;
+
+        lock (_lock)
+        {
+            foreach (var layer in _layers.Values)
+            {
+                layer.Dispose();
+            }
+            _layers.Clear();
+        }
+    }
+}