Fix modern RadioButton glyph clipping in RTL layouts (#14904)

## Proposed changes

- Added DPI-aware glyph padding in `RadioButtonModernAdapter`, preventing RTL hover clipping
- Added regression coverage in `RadioButtonTests`

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## Customer Impact

- RadioButton glyphs now render correctly without clipping when using `RightToLeft.Yes` with .NET 11 visual styles, including during mouse hover. The change also respects DPI scaling.

Author: LeafShi1

src/System.Windows.Forms/System/Windows/Forms/Controls/Buttons/ButtonInternal/RadioButtonModernAdapter.cs

@@ -61,6 +61,7 @@ protected override ButtonBaseAdapter CreateButtonAdapter()
     protected override LayoutOptions Layout(PaintEventArgs e)
     {
         LayoutOptions layout = CommonLayout();
+        layout.CheckPaddingSize = Control.LogicalToDeviceUnits(2);
         layout.CheckSize = Math.Max(
             Control.LogicalToDeviceUnits(13),
             (int)(Control.Font.Height * 0.9f));

src/test/unit/System.Windows.Forms/System/Windows/Forms/RadioButtonTests.cs

@@ -237,6 +237,35 @@ public void RadioButton_ModernGlyph_RendersAccentWhenChecked(bool isChecked, boo
         Assert.Equal(expectedAccent, CountPixels(bitmap, Color.Red) > 0);
     }
 
+    [WinFormsFact]
+    public void RadioButton_ModernGlyph_RightToLeftHovered_DoesNotClipAtRightEdge()
+    {
+        using Panel parent = new() { BackColor = Color.White };
+        using RadioButton control = new()
+        {
+            BackColor = Color.White,
+            RightToLeft = RightToLeft.Yes,
+            Size = new Size(40, 24),
+            VisualStylesMode = VisualStylesMode.Net11
+        };
+        control.FlatAppearance.BorderColor = Color.Black;
+        parent.Controls.Add(control);
+
+        control.TestAccessor.Dynamic.OnMouseEnter(EventArgs.Empty);
+        control.RadioGlyphRenderer.SetInteractionState(hovered: true, focused: false);
+        control.RadioGlyphRenderer.EndAnimation();
+        using Bitmap bitmap = new(control.Width, control.Height);
+        using Graphics graphics = Graphics.FromImage(bitmap);
+        PaintEventArgs e = new(graphics, control.ClientRectangle);
+
+        control.CreateStandardAdapter().PaintOver(e, CheckState.Unchecked);
+
+        for (int y = 0; y < bitmap.Height; y++)
+        {
+            Assert.Equal(0, bitmap.GetPixel(bitmap.Width - 1, y).A);
+        }
+    }
+
     [WinFormsFact]
     public void RadioButton_ModernGlyph_DefaultCheckedColorUsesWindowsAccent()
     {