fix: align animation pacing and transforms with native

engine/Age.Engine/Model/Transform2DMath.cs

@@ -0,0 +1,11 @@
+namespace Age.Engine.Model;
+
+/// <summary>The axis-aligned 2D reduction of AGE's row-vector object matrix. Native composition is
+/// T(-anchor) * scale * middle(rotation) * translation * T(anchor). With rotation deferred, a point is
+/// therefore anchor + (point-anchor)*scale + translation; Z remains a retained 3D channel, not opacity.</summary>
+public static class Transform2DMath
+{
+    public static (double X, double Y) Apply(double x, double y, TransformState transform)
+        => (transform.AnchorX + (x - transform.AnchorX) * transform.ScaleX + transform.TranslateX,
+            transform.AnchorY + (y - transform.AnchorY) * transform.ScaleY + transform.TranslateY);
+}