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

[trim] fully-unreachable files deleted: 6
[trim] files edited: 55, files deleted: 0, nodes removed: 244
[type-trim] files edited: 1, types removed: 1

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

SVSim.BattleEngine/Engine/SBattleLoad.cs

@@ -105,8 +105,6 @@ public class SBattleLoad : MonoBehaviour
 
 	public bool isDbgEnableEnemyHandView = true;
 
-	public bool isLoadEnd;
-
 	public TurnEndButtonUI m_TurnEndBtnUI { get; private set; }
 
 	public event Action OnEndWaitCallBack;