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/NetworkExecutionInfoCreator.cs

@@ -32,8 +32,6 @@ public class NetworkExecutionInfoCreator : ExecutionInfoCreatorBase
 
 	private bool _notNetwrokConditionCheck;
 
-	public const int SIDEN_NO_KOKUHYOU = 112241030;
-
 	public bool IsNotCheckBuriaRiteCondition { get; private set; }
 
 	public NetworkExecutionInfoCreator(SkillBase skill)
@@ -118,11 +116,11 @@ public class NetworkExecutionInfoCreator : ExecutionInfoCreatorBase
 					}
 					return true;
 				}
-				if ((_skill.IsUserSelectType || _skill.IsBurialRite) && ((GameMgr.GetIns().IsWatchBattle && _skill.SkillPrm.ownerCard.IsPlayer) || GameMgr.GetIns().IsAdminWatch))
+				if ((_skill.IsUserSelectType || _skill.IsBurialRite) && ((_networkBattleMgr.GameMgr.IsWatchBattle && _skill.SkillPrm.ownerCard.IsPlayer) || _networkBattleMgr.GameMgr.IsAdminWatch))
 				{
 					return result;
 				}
-				if (RegisterSkillConditionCheck.IsSkillConditionCheck(_skill, GameMgr.GetIns().IsAdmin))
+				if (RegisterSkillConditionCheck.IsSkillConditionCheck(_skill, _networkBattleMgr.GameMgr.IsAdmin))
 				{
 					return false;
 				}
@@ -175,7 +173,7 @@ public class NetworkExecutionInfoCreator : ExecutionInfoCreatorBase
 			return enumerable.Cast<BattleCardBase>().ToList();
 		}
 		return (from c in base.GetSelectableCards(playerInfoPair, option, isSkipForceSelect, selectedCards)
-			select (!GameMgr.GetIns().IsAdminWatch && !GameMgr.GetIns().IsReplayBattle && !c.IsPlayer && !c.IsInplay && !c.Card.IsInplay && !_skill.ApplyAndFilter.Any((ApplySkillTargetFilterCollection f) => f.TargetFilter is SkillTargetTurnPlayCardsOtherSelfFilter) && !_skill.ApplyAndFilter.Any((ApplySkillTargetFilterCollection f) => f.BattlePlayerFilter is OpponentBattlePlayerFilter && f.TargetFilter is SkillTargetGamePlayCardsOtherSelfFilter)) ? c.Card : c).ToList();
+			select (!_networkBattleMgr.GameMgr.IsAdminWatch && !_networkBattleMgr.GameMgr.IsReplayBattle && !c.IsPlayer && !c.IsInplay && !c.Card.IsInplay && !_skill.ApplyAndFilter.Any((ApplySkillTargetFilterCollection f) => f.TargetFilter is SkillTargetTurnPlayCardsOtherSelfFilter) && !_skill.ApplyAndFilter.Any((ApplySkillTargetFilterCollection f) => f.BattlePlayerFilter is OpponentBattlePlayerFilter && f.TargetFilter is SkillTargetGamePlayCardsOtherSelfFilter)) ? c.Card : c).ToList();
 	}
 
 	public override IEnumerable<BattleCardBase> CalcApplyTargets(BattlePlayerReadOnlyInfoPair playerInfoPair, SkillConditionCheckerOption option, ref int targetCount, bool isCheckInHand = false)
@@ -215,7 +213,7 @@ public class NetworkExecutionInfoCreator : ExecutionInfoCreatorBase
 	public override VfxWith<List<BattleCardBase>, Dictionary<int, BattleCardBase>> FixedSkillApplyTarget(BattlePlayerReadOnlyInfoPair playerInfoPair, SkillConditionCheckerOption option, ref int targetCount)
 	{
 		VfxWith<List<BattleCardBase>, Dictionary<int, BattleCardBase>> vfxWith;
-		if ((_skill.SkillPrm.ownerCard.IsPlayer && (!GameMgr.GetIns().IsWatchBattle || _networkBattleMgr.IsRecovery)) || GameMgr.GetIns().IsReplayBattle)
+		if ((_skill.SkillPrm.ownerCard.IsPlayer && (!_networkBattleMgr.GameMgr.IsWatchBattle || _networkBattleMgr.IsRecovery)) || _networkBattleMgr.GameMgr.IsReplayBattle)
 		{
 			IEnumerable<BattleCardBase> source = CalcApplyTargets(playerInfoPair, option, ref targetCount);
 			vfxWith = NotIndependentCardFiltering(source.ToList());
@@ -278,7 +276,7 @@ public class NetworkExecutionInfoCreator : ExecutionInfoCreatorBase
 
 	private bool IsUnapprovedSkill()
 	{
-		if (GameMgr.GetIns().IsWatchBattle)
+		if (_networkBattleMgr.GameMgr.IsWatchBattle)
 		{
 			if (_isUseUListOnlySelfTurnWhenAdmin)
 			{
@@ -307,11 +305,6 @@ public class NetworkExecutionInfoCreator : ExecutionInfoCreatorBase
 		_isAllDeckCardTarget = true;
 	}
 
-	public void SetUseUListOnlySelfTurn()
-	{
-		_isUseUListOnlySelfTurnWhenAdmin = true;
-	}
-
 	public void SetValidateConditionCheckSkill()
 	{
 		_validateSkillCheckFlag = true;
@@ -352,11 +345,6 @@ public class NetworkExecutionInfoCreator : ExecutionInfoCreatorBase
 		return _skillMovementNum;
 	}
 
-	public void SetNotNetwrokConditionCheck(bool flag)
-	{
-		_notNetwrokConditionCheck = flag;
-	}
-
 	private List<BattleCardBase> CalculationUnapprovedCardList(int skillIndex)
 	{
 		BattlePlayerBase selfBattlePlayer = _skill.SkillPrm.ownerCard.SelfBattlePlayer;