fix(dock): move dock math to core to fix test suite breakage

src/Editor/Ghost.Editor.Core/Controls/Internal/Docking/DockMath.cs

@@ -0,0 +1,33 @@
+namespace Ghost.Editor.Core.Controls.Internal.Docking;
+
+/// <summary>
+/// Defines the possible dock positions for a drop operation.
+/// </summary>
+public enum DockPosition
+{
+    Center,
+    Top,
+    Bottom,
+    Left,
+    Right,
+    None
+}
+
+/// <summary>
+/// Helper class for docking-related calculations.
+/// </summary>
+public static class DockMath
+{
+    /// <summary>
+    /// Calculates the dock position based on the relative position within a target element.
+    /// Precedence: Left/Right win over Top/Bottom at corners.
+    /// </summary>
+    public static DockPosition CalculateDockPosition(double width, double height, double x, double y, double threshold)
+    {
+        if (x < width * threshold) return DockPosition.Left;
+        if (x > width * (1 - threshold)) return DockPosition.Right;
+        if (y < height * threshold) return DockPosition.Top;
+        if (y > height * (1 - threshold)) return DockPosition.Bottom;
+        return DockPosition.Center;
+    }
+}