cull(engine-cleanup): pass-8 phase-2 cascade round 1 after AreaSelectUI stub

SVSim.BattleEngine/Engine/AreaSelectUI.cs

@@ -8,9 +8,6 @@ using Wizard.Battle.Recovery;
 // See Task 2b of PASS8-PLAN.md.
 public class AreaSelectUI : UIBase
 {
-    public bool IsUseChapterListClearedMask { get; private set; }
-
-    public string GetChapterTitleStory(string chapterID) => null;
 
     public static void SetRecoveryData(SetupConditionInfo setupInfo) { }
 }