cull(engine-cleanup): pass-8 phase-2 cascade round 2

[trim] fully-unreachable files deleted: 3
[trim] files edited: 21, files deleted: 0, nodes removed: 38
[type-trim] files edited: 3, types removed: 3

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

SVSim.BattleEngine/Engine/Mail.cs

@@ -469,13 +469,6 @@ public class Mail : UIBase
 		// method becomes a no-op (the scroll wrap paths above handle empty results cleanly).
 	}
 
-	private void UpdateScrollSize()
-	{
-		WrapContent.minIndex = -(_currentList.Count - 1);
-		WrapScrollbar.ContentUpdate();
-		ScrollView.UpdateScrollbars();
-	}
-
 	protected override void onClose()
 	{
 		base.onClose();