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/LitJson/ObjectMetadata.cs

@@ -0,0 +1,53 @@
+using System;
+using System.Collections.Generic;
+
+namespace LitJson;
+
+internal struct ObjectMetadata
+{
+	private Type element_type;
+
+	private bool is_dictionary;
+
+	private IDictionary<string, PropertyMetadata> properties;
+
+	public Type ElementType
+	{
+		get
+		{
+			if (element_type == null)
+			{
+				return typeof(JsonData);
+			}
+			return element_type;
+		}
+		set
+		{
+			element_type = value;
+		}
+	}
+
+	public bool IsDictionary
+	{
+		get
+		{
+			return is_dictionary;
+		}
+		set
+		{
+			is_dictionary = value;
+		}
+	}
+
+	public IDictionary<string, PropertyMetadata> Properties
+	{
+		get
+		{
+			return properties;
+		}
+		set
+		{
+			properties = value;
+		}
+	}
+}