port(m1): wave 6a — GameMgr setters, Tab MonoBehaviour, OpeningVfx members, Vfx stubs (838->772)

- GameMgr.Is{Network,AINetwork,Watch,Replay,Puzzle,AdminWatch}Battle: read-only => settable (CS0200, Matching/NetworkBattleManagerBase assign them).
- Tab : MonoBehaviour (inherits Object.name; CS1061 x8).
- OpeningVfx: static OpenningLogStep, ShowBattleUIImmediatelyVfx (NullVfx, F1 contract), nested WaitVoiceEndVfx (CS0117/0426 x14).
- Generated no-op stubs EffectBattleVfxBase/SkillEffectBattleVfx/FallToGroundVfx/ThinkIconShowVfx (: SequentialVfxPlayer chain), baseclauses reattached.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

SVSim.BattleEngine/Shim/GodObjects/GodObjects.cs

@@ -79,12 +79,12 @@ public class GameMgr
     public DateTime AnnounceTime;
     public Wizard.RankWinnerReward _rankWinnerReward;
 
-    public bool IsAdminWatch => false;
-    public bool IsWatchBattle => false;
-    public bool IsReplayBattle => false;
-    public bool IsNetworkBattle => false;
-    public bool IsAINetwork => false;
-    public bool IsPuzzleQuest => false;
+    public bool IsAdminWatch { get; set; }
+    public bool IsWatchBattle { get; set; }
+    public bool IsReplayBattle { get; set; }
+    public bool IsNetworkBattle { get; set; }
+    public bool IsAINetwork { get; set; }
+    public bool IsPuzzleQuest { get; set; }
 
     private EffectMgr _effect;
     private SoundMgr _sound;