feat(battle-engine): full Unity/VFX/god-object shims + expanded copy closure (2570 files)

Authored Unity primitive/object-model shim, VFX layer (control-flow-preserving, InstantVfx never invokes its action -- headless suppression), god-object stubs (GameMgr/EffectMgr/UIManager with faithfully-extracted nested enums), View/UI/Touch tree, LitJson+BetterList+Tuple copied, third-party stubs. Discovered Roslyn header-error masking: fixing class-header type errors unmasks body references, so the true copy closure is ~2570 files (was 782 under masking). Errors: masked-25720 -> 268; our shim files compile clean. Remaining: ~50 residual shim/external types, 24 NGUI UI-base overrides, static-type fixes, plus likely 1-2 more unmask waves.

SVSim.BattleEngine/Engine/Wizard/DiscardedVirtualCard.cs

@@ -0,0 +1,28 @@
+using System.Collections.Generic;
+
+namespace Wizard;
+
+public class DiscardedVirtualCard : AIVirtualCard
+{
+	public DiscardedVirtualCard(BattleCardBase card, AIVirtualField field)
+	{
+		_field = field;
+		base.IsAlly = true;
+		InitializeFromBattleCardBase(card);
+	}
+
+	public override bool IsFollower(List<int> playPtn)
+	{
+		return IsUnit;
+	}
+
+	protected override void InitializeFromBattleCardBase(BattleCardBase origin)
+	{
+		InitializeFromBattleCardBaseBasic(origin);
+		Cost = origin.Cost;
+		IsPlayer = origin.IsPlayer;
+		IsLeader = false;
+		IsSelfTurn = origin.IsSelfTurn;
+		base.DestroyedTurn = origin.DestroyedTurn;
+	}
+}