feat(ai): 新增 IBossControl facet——Boss 阶段状态经 IAiContext 供图读取

非 Boss 敌人访问 IAiContext.Boss 显式抛 InvalidOperationException，
不返回空对象掩盖小怪图误挂 Boss 边的错误。BossResource 补 IsFull 供图条件边判定。

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Assets/Tests/EditMode/AI/Fakes/FakeAiContext.cs

@@ -51,10 +51,12 @@ namespace BaseGames.Tests.EditMode.AI
         public FakeCombat C = new FakeCombat();
         public FakeVitals V = new FakeVitals();
         public Blackboard BB = new Blackboard();
+        public FakeBossControl B = new FakeBossControl();
         public ISensor Sensor => S;
         public IEnemyLocomotion Locomotion => L;
         public ICombatant Combat => C;
         public IActorVitals Vitals => V;
         public Blackboard Blackboard => BB;
+        public IBossControl Boss => B;
     }
 }