feat(battle-engine): close the AI-simulation subsystem (verbatim)

Copied the 89 uncopied AI*SimulationUtility/extension files defining the
AIVirtualCard/AIVirtualField extension methods; the compile loop then auto-closed
the revealed type deps (~3049 files total, drift-clean). 10.0k -> 62 errors.

SVSim.BattleEngine/Engine/ClipboardHelper.cs

@@ -0,0 +1,16 @@
+using UnityEngine;
+
+public class ClipboardHelper
+{
+	public static string Clipboard
+	{
+		get
+		{
+			return GUIUtility.systemCopyBuffer;
+		}
+		set
+		{
+			GUIUtility.systemCopyBuffer = value;
+		}
+	}
+}