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/Wizard.Battle.Phase/SingleMulliganPhase.cs

@@ -0,0 +1,12 @@
+using Wizard.Battle.Mulligan;
+
+namespace Wizard.Battle.Phase;
+
+public class SingleMulliganPhase : MulliganPhaseBase
+{
+	public SingleMulliganPhase(BattleManagerBase battleMgr)
+		: base(battleMgr)
+	{
+		Initialize(new SingleMulliganMgr());
+	}
+}