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/BattleCamera.cs

@@ -9,10 +9,6 @@ public class BattleCamera
 
 	public Camera _backgroundCamera;
 
-	public Vector3 BattleCameraPos { get; private set; }
-
-	public Vector3 BattleCameraRot { get; private set; }
-
 	public BattleCamera()
 	{
 		Camera = null;