Preview 3: Complete control implementation with XAML data binding

Major milestone adding full control functionality:

Controls Enhanced:
- Entry/Editor: Full keyboard input, cursor navigation, selection, clipboard
- CollectionView: Data binding, selection highlighting, scrolling
- CheckBox/Switch/Slider: Interactive state management
- Picker/DatePicker/TimePicker: Dropdown selection with popup overlays
- ProgressBar/ActivityIndicator: Animated progress display
- Button: Press/release visual states
- Border/Frame: Rounded corners, stroke styling
- Label: Text wrapping, alignment, decorations
- Grid/StackLayout: Margin and padding support

Features Added:
- DisplayAlert dialogs with button actions
- NavigationPage with toolbar and back navigation
- Shell with flyout menu navigation
- XAML value converters for data binding
- Margin support in all layout containers
- Popup overlay system for pickers

New Samples:
- TodoApp: Full CRUD task manager with NavigationPage
- ShellDemo: Comprehensive control showcase

Removed:
- ControlGallery (replaced by ShellDemo)
- LinuxDemo (replaced by TodoApp)

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

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

Views/SkiaSearchBar.cs

@@ -55,9 +55,11 @@ public class SkiaSearchBar : SkiaView
         _entry = new SkiaEntry
         {
             Placeholder = "Search...",
+            EntryBackgroundColor = SKColors.Transparent,
             BackgroundColor = SKColors.Transparent,
             BorderColor = SKColors.Transparent,
-            FocusedBorderColor = SKColors.Transparent
+            FocusedBorderColor = SKColors.Transparent,
+            BorderWidth = 0
         };
 
         _entry.TextChanged += (s, e) =>
@@ -193,12 +195,24 @@ public class SkiaSearchBar : SkiaView
             return;
         }
 
-        // Forward to entry for text input focus
+        // Forward to entry for text input focus and selection
         _entry.IsFocused = true;
         IsFocused = true;
+        _entry.OnPointerPressed(e);
         Invalidate();
     }
 
+    public override void OnPointerMoved(PointerEventArgs e)
+    {
+        if (!IsEnabled) return;
+        _entry.OnPointerMoved(e);
+    }
+
+    public override void OnPointerReleased(PointerEventArgs e)
+    {
+        _entry.OnPointerReleased(e);
+    }
+
     public override void OnTextInput(TextInputEventArgs e)
     {
         _entry.OnTextInput(e);