feat: Implement Room Streaming System

- Add RoomStreamingManager to manage room loading and unloading based on player proximity.
- Create StreamingBudgetConfigSO for memory and performance budgeting of the streaming system.
- Introduce TransitionDirector to handle seamless and atmospheric fade transitions between rooms.
- Develop WorldGraph to represent room connectivity and facilitate neighbor queries and distance calculations.
- Implement RoomNode and RoomEdge classes to structure room data and connections.

Assets/_Game/Scripts/Enemies/Boss/BossSkillSO.cs

@@ -12,9 +12,12 @@ namespace BaseGames.Boss
     public class BossSkillSO : ScriptableObject
     {
         [Header("元信息")]
+        [Tooltip("技能唯一标识符（全小写英文 + 下划线，如 'slash_combo'、'phase_dash'）。BD_UseBossSkill 通过此 Id 引用")]
         public string         skillId;
+        [Tooltip("编辑器中显示的可读名称，不影响运行逻辑")]
         public string         displayName;
         [TextArea(1, 4)]
+        [Tooltip("设计备注（仅供编辑器参考，不影响运行）")]
         public string         designNote;
 
         [Header("技能分类")]
@@ -57,5 +60,10 @@ namespace BaseGames.Boss
         [Header("冷却")]
         [Min(0f)]
         public float cooldown;
+
+        [Header("权重随机（UseBossSkillWeighted 使用）")]
+        [Tooltip("相对权重，数值越大被随机选中的概率越高；0 = 禁用随机选择")]
+        [Min(0f)]
+        public float weight = 1f;
     }
 }