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/Skill_extra_turn.cs

@@ -0,0 +1,38 @@
+using Wizard.Battle.View.Vfx;
+
+public class Skill_extra_turn : SkillBase
+{
+	public Skill_extra_turn(SkillParameter skillPrm, string option)
+		: base(skillPrm, option)
+	{
+	}
+
+	public override VfxWithLoading Start(CallParameter parameter)
+	{
+		if (BattleManagerBase.IsForecast)
+		{
+			return NullVfxWithLoading.GetInstance();
+		}
+		int addTurn = GetAddTurn();
+		ParallelVfxPlayer parallelVfxPlayer = ParallelVfxPlayer.Create();
+		foreach (BattleCardBase targetCard in parameter.targetCards)
+		{
+			VfxBase vfx = targetCard.SkillApplyInformation.GiveExtraTurn(addTurn);
+			parallelVfxPlayer.Register(vfx);
+		}
+		VfxWithLoadingSequential vfxWithLoadingSequential = VfxWithLoadingSequential.Create();
+		vfxWithLoadingSequential.RegisterVfxWithLoading(CreateSkillEffect(base.SkillPrm.resourceMgr, parameter.targetCards));
+		vfxWithLoadingSequential.RegisterToMainVfx(parallelVfxPlayer);
+		return vfxWithLoadingSequential;
+	}
+
+	public int GetAddTurn()
+	{
+		return base.OptionValue.GetInt(SkillFilterCreator.ContentKeyword.add, 0);
+	}
+
+	public override VfxWithLoading Stop(SkillProcessor skillProcessor)
+	{
+		return base.Stop(skillProcessor);
+	}
+}