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/CardMake.cs

@@ -138,14 +138,4 @@ public class CardMake : MonoBehaviour
 		int possessionCardNum = 0; // Pre-Phase-5b: headless has no user inventory
 		return $"{num},{possessionCardNum}";
 	}
-
-	private void OnError(NetworkTask.ResultCode code)
-	{
-		OnClose.Call();
-	}
-
-	private void OnError(int code)
-	{
-		OnClose.Call();
-	}
 }