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/MailData.cs

@@ -0,0 +1,40 @@
+using System;
+using LitJson;
+using Wizard;
+
+public class MailData : HeaderData
+{
+	public int mail_id;
+
+	public string message;
+
+	public int reward_type;
+
+	public long reward_count;
+
+	public int item_type;
+
+	public string create_time;
+
+	public int limit_type;
+
+	public long reward_limit_time;
+
+	public long RewardUserGoodsId { get; set; }
+
+	public MailData(JsonData data)
+	{
+		mail_id = data["present_id"].ToInt();
+		message = data["message"].ToString();
+		reward_type = data["reward_type"].ToInt();
+		RewardUserGoodsId = data["reward_detail_id"].ToLong();
+		reward_count = data["reward_count"].ToLong();
+		if (reward_type == 4)
+		{
+			item_type = data["item_type"].ToInt();
+		}
+		create_time = ConvertTime.ToLocal(DateTime.Parse(data["create_time"].ToString()));
+		limit_type = data["present_limit_type"].ToInt();
+		reward_limit_time = data["reward_limit_time"].ToLong();
+	}
+}