draw score juxtaposed on box relative to head

src/Arts.cs

@@ -250,6 +250,19 @@ static class Arts
                 )
             );
         }
+
+        // score
+        Quat score_ori = Quat.LookDir(Rig.head.position - Mono.box_pose.position);
+        Text.Add(
+            Mono.snake_len.ToString("000"),
+            Matrix.TRS(
+                score_ori * V.XYZ(0, -Mono.SD_Y - 1, -Mono.SD_Z - 1),
+                score_ori,
+                32
+            ),
+            text_style
+        );
+
         Hierarchy.Pop();
 
         // for (int sx = -Mono.head_fill.Xslen; Mono.head_fill.InX(sx); sx++)