Update with recovered code from VM binaries (Jan 1)

Recovered from decompiled OpenMaui.Controls.Linux.dll:
- SkiaShell.cs: FlyoutHeader, FlyoutFooter, scroll support (918 -> 1325 lines)
- X11Window.cs: Cursor support (XCreateFontCursor, XDefineCursor)
- All handlers with dark mode support
- All services with latest implementations
- LinuxApplication with theme change handling

Services/NullInputMethodService.cs

@@ -0,0 +1,43 @@
+using System;
+
+namespace Microsoft.Maui.Platform.Linux.Services;
+
+public class NullInputMethodService : IInputMethodService
+{
+	public bool IsActive => false;
+
+	public string PreEditText => string.Empty;
+
+	public int PreEditCursorPosition => 0;
+
+	public event EventHandler<TextCommittedEventArgs>? TextCommitted;
+
+	public event EventHandler<PreEditChangedEventArgs>? PreEditChanged;
+
+	public event EventHandler? PreEditEnded;
+
+	public void Initialize(IntPtr windowHandle)
+	{
+	}
+
+	public void SetFocus(IInputContext? context)
+	{
+	}
+
+	public void SetCursorLocation(int x, int y, int width, int height)
+	{
+	}
+
+	public bool ProcessKeyEvent(uint keyCode, KeyModifiers modifiers, bool isKeyDown)
+	{
+		return false;
+	}
+
+	public void Reset()
+	{
+	}
+
+	public void Shutdown()
+	{
+	}
+}