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/DeckListUtility.cs

@@ -104,25 +104,6 @@ public static class DeckListUtility
 		return list;
 	}
 
-	public static void SetDeckListDataWithLodeIndex()
-	{
-		LoadDetail data = Data.Load.data;
-		DeckListUpdate(CreateDeckGroup(data.UserDeckListUnlimited, Format.Unlimited, DeckAttributeType.CustomDeck));
-		DeckListUpdate(CreateDeckGroup(data.UserDeckListRotation, Format.Rotation, DeckAttributeType.CustomDeck));
-		if (data.UserDeckListPreRotation != null)
-		{
-			DeckListUpdate(CreateDeckGroup(data.UserDeckListPreRotation, Format.PreRotation, DeckAttributeType.CustomDeck));
-		}
-		if (data.UserDeckListCrossover != null)
-		{
-			DeckListUpdate(CreateDeckGroup(data.UserDeckListCrossover, Format.Crossover, DeckAttributeType.CustomDeck));
-		}
-		if (data.UserDeckListMyRotation != null)
-		{
-			DeckListUpdate(CreateDeckGroup(data.UserDeckListMyRotation, Format.MyRotation, DeckAttributeType.CustomDeck));
-		}
-	}
-
 	private static void DeckListUpdate(DeckGroup receiveDeckGroup)
 	{
 		DeckGroup deckGroup = DeckGroupDataBase.FirstOrDefault((DeckGroup d) => d.DeckFormat == receiveDeckGroup.DeckFormat && d.AttributeType == receiveDeckGroup.AttributeType);
@@ -196,7 +177,7 @@ public static class DeckListUtility
 
 	public static void DataMgrSaveLastSelectDeckData(DeckData deckData)
 	{
-		DataMgr dataMgr = GameMgr.GetIns().GetDataMgr();
+		DataMgr dataMgr = null; // Pre-Phase-5b: headless has no DataMgr
 		dataMgr.SetSelectDeckId(deckData.GetDeckID());
 		dataMgr.SetPlayerCharaIdBySkinId(deckData.GetSkinId());
 		dataMgr.SetCurrentDeckData(deckData.GetCardIdList());
@@ -267,42 +248,11 @@ public static class DeckListUtility
 		}
 	}
 
-	public static List<DeckGroup> ConvertSkinOverrideDeckGroupList(List<DeckGroup> deckGroupList, Dictionary<int, int> dictDeckSkinIdOverride)
-	{
-		List<DeckGroup> list = new List<DeckGroup>();
-		foreach (DeckGroup deckGroup in deckGroupList)
-		{
-			List<DeckData> list2 = new List<DeckData>();
-			foreach (DeckData deckData in deckGroup.DeckDataList)
-			{
-				list2.Add(CopyAndReplaceDeckSkinOverride(deckData, dictDeckSkinIdOverride));
-			}
-			list.Add(new DeckGroup(list2, deckGroup.DeckFormat, deckGroup.AttributeType));
-		}
-		return list;
-	}
-
-	private static DeckData CopyAndReplaceDeckSkinOverride(DeckData deck, Dictionary<int, int> dictDeckSkinIdOverride)
-	{
-		DeckData deckData = deck.Clone();
-		if (deckData.IsNoCard())
-		{
-			return deckData;
-		}
-		int deckClassID = deckData.GetDeckClassID();
-		if (dictDeckSkinIdOverride.TryGetValue(deckClassID, out var value))
-		{
-			deckData.SetSkinId(value);
-		}
-		deckData.IsReplaceDeckSkin = true;
-		return deckData;
-	}
-
 	private static void SetLeaderSkinSetting(JsonData jsonData)
 	{
 		for (int i = 0; i < jsonData.Count; i++)
 		{
-			DataMgr dataMgr = GameMgr.GetIns().GetDataMgr();
+			DataMgr dataMgr = null; // Pre-Phase-5b: headless has no DataMgr
 			int classId = jsonData[i]["class_id"].ToInt();
 			ClassCharaPrm classPrm = dataMgr.GetClassPrm(classId);
 			classPrm.IsRandomLeaderSkin = jsonData[i]["is_random_leader_skin"].ToBoolean();
@@ -311,19 +261,4 @@ public static class DeckListUtility
 			classPrm.SetCurrentCharaId(charaPrmBySkinId.chara_id);
 		}
 	}
-
-	public static List<DeckGroup> StoryDeckSelectClass(List<DeckGroup> deckGroups, int classId)
-	{
-		List<DeckGroup> list = new List<DeckGroup>();
-		foreach (DeckGroup deckGroup in deckGroups)
-		{
-			List<DeckData> list2 = deckGroup.DeckDataList;
-			if (deckGroup.AttributeType == DeckAttributeType.BuildDeck || deckGroup.AttributeType == DeckAttributeType.TrialDeck)
-			{
-				list2 = list2.Where((DeckData d) => d.GetDeckClassID() == classId || d.IsNoCard()).ToList();
-			}
-			list.Add(new DeckGroup(list2, deckGroup.DeckFormat, deckGroup.AttributeType));
-		}
-		return list;
-	}
 }