remove demo game

scene.camera.go

@@ -0,0 +1,10 @@
+package pncdsl
+
+// Camera is a stub identity transform — no scrolling in this milestone.
+type Camera struct {
+	Offset Point
+}
+
+func NewCamera() *Camera { return &Camera{} }
+
+func (c *Camera) Apply(p Point) Point { return Point{p.X - c.Offset.X, p.Y - c.Offset.Y} }