engine cleanup passes 4-7 + multi-instancing ambient rip

Squashes 146 commits from battle-engine-extraction. Net: 2,045 files changed,
+11,896 / -158,687 lines. Ships engine passes 4-7 (dead-code cull, view-layer
stub, receive-path shrink) plus the Phase-5 AsyncLocal ambient deletion that
turns concurrent battles into a type-system property rather than a scope
contract.

## What landed

**Passes 4-7 (chunks 1-34):** Extended the Phase-4 const-false collapse into a
cascading cull across the skill graph, view layer, and receive-path periphery.
Six mode flags (IsWatchBattle/IsReplayBattle/IsAdmin/IsAdminWatch/IsPuzzleQuest/
IsAINetwork) became `const false`, every guarded block deleted. Field*.cs
subclass ctors + BackGroundBase + ObjectChecker culled to no-ops. Mulligan
family reworked to take a mgr param through IMulliganMgr.InitMulligan.
Emotion/Recovery/Resource clusters null-stubbed. Prediction/OperationSimulator/
skill filters converted from static ambient reads to per-mgr reads via
SkillPrm.ownerCard.SelfBattlePlayer.BattleMgr / ins.BattleMgr / this.BattleMgr.

**Phase-5 ambient rip (chunks 35-47):** Deleted BattleAmbient / BattleAmbient-
Context / TestBattleScope in full. Every per-battle mutable slot now lives on
the mgr instance itself:
  mgr.InstanceIsForecast / InstanceIsRandomDraw / InstanceRecoveryInfo /
  InstanceViewerId / InstanceNetworkAgent / GameMgr
BattleManagerBase.GetIns() returns null unconditionally; the residual static
flags + 3 façades (Certification.ViewerId, Data.BattleRecoveryInfo,
ToolboxGame.RealTimeNetworkAgent) are null-tolerant defaults kept for the
handful of engine-internal readers that still reference their types. Zero
BattleAmbient references anywhere in engine + node + tests.

Added pre-seeded GameMgr ctor overload threaded through the mgr chain
(BattleManagerBase → SingleBattleMgr / NetworkBattleManagerBase → NetworkStandard-
BattleMgr → HeadlessBattleMgr / HeadlessNetworkBattleMgr). Fixtures build a
GameMgr, seed it via HeadlessEngineEnv.SeedCharaIds/SeedNetUser, and pass it
to the mgr's ctor — no ambient reach.

Node side (SVSim.BattleNode/SessionBattleEngine): _ctx replaced with a plain
GameMgr field; 34 `using var _ambient = BattleAmbient.Enter(_ctx)` scope wraps
ripped from every accessor and mutator; EngineGlobalInit.WirePerSessionGameMgr
takes GameMgr as a param and runs from SessionBattleEngine.SetupInternal
BEFORE mgr construction.

Test side: TestBattleScope deleted; 18 fixture [SetUp]s migrated to
`HeadlessEngineEnv.EnsureProcessGlobals()`; MultiInstanceEngineTests rewritten
around per-mgr construction (GetIns() → null is the pinned invariant).

## Regression fixes

- **chunk-48** (MulliganCtrl): chunk-35's `= null` stubs on card lookups broke
  the live receive-driven Deal path (BattlePlayerBase.DrawCard NRE'd downstream
  of NetworkPlayerMulliganCtrl.StartMulliganVfx). Restored the three lookups
  via `_battlePlayer.BattleMgr.GetBattleCardIdx`. Engine tests were satisfied
  by the WireMulliganPhase seam; unit tests exposed the live-path gap.

## Ship state

- SVSim.BattleEngine.Tests: 56/56 pass, 2 skip
- SVSim.UnitTests: 1554/1554 pass (was 1523/31-fail before chunk 48)
- Solution build: 0 source warnings (40 pre-existing NU1902 MessagePack CVEs
  in SVSim.EmulatedEntrypoint, unrelated)
- Sequential PVP smoke: verified live (two back-to-back battles, no regression
  on cleanup/spinup)
- Concurrent PVP smoke: verified live

Adds tools/engine-port/ClosureAnalyzer/ — the Roslyn transitive-type-closure
analyzer needed to make future cascade cleanup safe (per feedback memory
"Engine cleanup needs closure tool" from the 2026-06-28 pass-3 failure).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

SVSim.BattleEngine/Engine/Wizard/GachaResultBuyCardPack.cs

@@ -8,20 +8,15 @@ namespace Wizard;
 
 public class GachaResultBuyCardPack : UIBase
 {
-	private const int MAX_ROW_IN_PAGE = 2;
 
 	private readonly int[] MAX_COLUMN_RARELITY = new int[4] { 8, 8, 8, 8 };
 
-	private const float CARD_SCALE = 0.55f;
-
 	private readonly Vector3 GRID_LOCAL_POSITION = Vector3.up * -6f;
 
 	private readonly Vector3 GRID_ONLY_ONE_LOCAL_POSITION = Vector3.up * -15f;
 
 	private readonly Vector3 NEW_LABEL_POSITION = Vector3.up * -150f;
 
-	private const string FREE_PACK_LEADER_SKIN_EFFECT = "gch_result_skin_1";
-
 	private bool m_isCenterLoading;
 
 	[SerializeField]
@@ -117,22 +112,6 @@ public class GachaResultBuyCardPack : UIBase
 
 	public bool IsDialogCloseStart { get; set; }
 
-	private void Update()
-	{
-		if (!m_isCenterLoading && m_isInitLoadFinish && GameMgr.GetIns().GetInputMgr().IsFlick() && IsFlickEnable)
-		{
-			if (GameMgr.GetIns().GetInputMgr().GetFlickVec()
-				.x < 0f)
-			{
-				OnNextButton();
-			}
-			else
-			{
-				OnPrevButton();
-			}
-		}
-	}
-
 	public void Init(List<CardPack> cardPackList, CardDetailUI cardDetailUI)
 	{
 		m_cardDetailUI = cardDetailUI;
@@ -325,24 +304,6 @@ public class GachaResultBuyCardPack : UIBase
 		}
 	}
 
-	public void OnNextButton()
-	{
-		if (!m_isCenterLoading && m_isInitLoadFinish && !IsDialogCloseStart && !m_cardDetailUI.GetIsDetailOn() && currentPage < m_CardPackListPerPage.Count)
-		{
-			StartCoroutine(ViewCardList(++currentPage));
-			GameMgr.GetIns().GetSoundMgr().PlaySe(Se.TYPE.SYS_SLIDE_BTN);
-		}
-	}
-
-	public void OnPrevButton()
-	{
-		if (!m_isCenterLoading && m_isInitLoadFinish && !IsDialogCloseStart && !m_cardDetailUI.GetIsDetailOn() && currentPage > 1)
-		{
-			StartCoroutine(ViewCardList(--currentPage));
-			GameMgr.GetIns().GetSoundMgr().PlaySe(Se.TYPE.SYS_SLIDE_BTN);
-		}
-	}
-
 	private List<CardPack> SortCardList(List<CardPack> cardList)
 	{
 		List<int> idList = cardList.ConvertAll((CardPack conv) => conv.card_id);
@@ -471,7 +432,7 @@ public class GachaResultBuyCardPack : UIBase
 				_particleGroup.StartEffect(param, isEnableUpdateReposition: true);
 			}
 			cardObj.transform.localPosition += Vector3.back;
-			if (GameMgr.GetIns().GetDataMgr().IsNewCard(cardObjList[i].ids))
+			if (false /* Pre-Phase-5b: no new-card state headless */)
 			{
 				cardObj.GetComponent<CardListTemplate>()._newLabel.transform.localPosition = NEW_LABEL_POSITION;
 			}