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/ChantCountSetModifier.cs

@@ -0,0 +1,21 @@
+public class ChantCountSetModifier : ICardChantCountModifier
+{
+	public readonly int ChantCount;
+
+	public bool IsClearBeforeModifier => true;
+
+	public ChantCountSetModifier(int chantCount)
+	{
+		ChantCount = chantCount;
+	}
+
+	public int CalcChantCount(int chantCount)
+	{
+		return ChantCount;
+	}
+
+	public ICardChantCountModifier Clone()
+	{
+		return new ChantCountSetModifier(ChantCount);
+	}
+}