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/Cute/ParallelJob.cs

@@ -0,0 +1,36 @@
+using System;
+
+namespace Cute;
+
+public class ParallelJob
+{
+	private Action _action;
+
+	public bool isDone { get; private set; }
+
+	public static ParallelJob Dispatch(Action action)
+	{
+		ParallelJob parallelJob = new ParallelJob(action);
+		LeanThreadPool.Instance.AddJob(parallelJob);
+		return parallelJob;
+	}
+
+	private ParallelJob(Action action)
+	{
+		isDone = false;
+		_action = action;
+	}
+
+	internal void Run()
+	{
+		if (!isDone)
+		{
+			if (_action != null)
+			{
+				_action();
+				_action = null;
+			}
+			isDone = true;
+		}
+	}
+}