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/DeckSelectUI.cs

@@ -131,14 +131,6 @@ public class DeckSelectUI : MonoBehaviour
 		}
 	}
 
-	private const int MAXNUM_DECK_PER_TABLE = 9;
-
-	private const float DRAG_DEGREE = 70f;
-
-	private const float PAGE_INTERVAL = 1400f;
-
-	private const float MOVE_PAGE_DURATION = 0.2f;
-
 	private static readonly Vector3 VIEW_PAGE_POSITION = Vector3.zero;
 
 	private static readonly Vector3 OUTSIDE_RIGHT_PAGE_POSITION = VIEW_PAGE_POSITION + Vector3.right * 1400f;
@@ -180,9 +172,6 @@ public class DeckSelectUI : MonoBehaviour
 	[SerializeField]
 	private UIGrid[] _deckTableGrids = new UIGrid[2];
 
-	[SerializeField]
-	private UIPanel _panel;
-
 	[SerializeField]
 	private UIButton _infoButton;
 
@@ -236,7 +225,7 @@ public class DeckSelectUI : MonoBehaviour
 			UIEventListener uIEventListener4 = UIEventListener.Get(_infoButton.gameObject);
 			uIEventListener4.onClick = (UIEventListener.VoidDelegate)Delegate.Combine(uIEventListener4.onClick, (UIEventListener.VoidDelegate)delegate
 			{
-				GameMgr.GetIns().GetSoundMgr().PlaySe(Se.TYPE.SYS_COMMON_BUTTON);
+
 				initOptions.OnClickInfoButton.Call();
 			});
 		}
@@ -274,20 +263,9 @@ public class DeckSelectUI : MonoBehaviour
 		});
 	}
 
-	public void ShowCautionText(string cautionText)
-	{
-		_cautionLabel.gameObject.SetActive(cautionText != string.Empty);
-		_cautionLabel.text = cautionText;
-	}
-
-	public void UpdateAllDeckUICurrentPage()
-	{
-		_deckTables[_deckTableIndex].UpdateDeckViewList(_pageList[_currentPageIndex].DeckViewList, _canUseNonPossessionCard);
-	}
-
 	private void OnClickDeck(DeckUI deckUI)
 	{
-		GameMgr.GetIns().GetSoundMgr().PlaySe(Se.TYPE.SYS_COMMON_BUTTON);
+
 		OnSelectDeck.Call(deckUI.Deck);
 	}
 
@@ -446,13 +424,7 @@ public class DeckSelectUI : MonoBehaviour
 		{
 			IsPageMoving = false;
 		});
-		GameMgr.GetIns().GetSoundMgr().PlaySe(Se.TYPE.SYS_SLIDE_BTN);
-	}
 
-	private void OnDestroy()
-	{
-		_isOnDestroy = true;
-		DeleteResource();
 	}
 
 	private void DeleteResource()
@@ -463,9 +435,4 @@ public class DeckSelectUI : MonoBehaviour
 			_resourcePathList.Clear();
 		}
 	}
-
-	public void SetPanelDepth(int depth)
-	{
-		_panel.depth = depth;
-	}
 }