feat(渲染): 重构渲染层级管理并添加BOSS层级

移除动态渲染层级更新逻辑，改为在实体加载时设置固定层级
- 在Hero和Monster的load方法中设置初始siblingIndex
- 添加BOSS枚举值到IndexSet
- 为Monster添加溢出保护，防止层级索引过大
- 删除墓地位置判断等不再需要的逻辑

assets/script/game/hero/Hero.ts

@@ -4,7 +4,7 @@ import { ecs } from "../../../../extensions/oops-plugin-framework/assets/libs/ec
 import { smc } from "../common/SingletonModuleComp";
 import { HeroAttrsComp } from "./HeroAttrsComp";
 import { HeroViewComp } from "./HeroViewComp";
-import { BoxSet, FacSet } from "../common/config/GameSet";
+import { BoxSet, FacSet, IndexSet } from "../common/config/GameSet";
 import { HeroInfo, HeroPos, HType } from "../common/config/heroSet";
 import { GameEvent } from "../common/config/GameEvent";
 import { SkillSet } from "../common/config/SkillSet";
@@ -50,6 +50,11 @@ export class Hero extends ecs.Entity {
         const collider = node.getComponent(BoxCollider2D);
         if (collider) collider.enabled = false; // 先禁用
         node.setPosition(pos)
+        
+        // 🔥 设置初始 SiblingIndex - 英雄基础层级 + 位置偏移
+        const initialSiblingIndex = IndexSet.HERO;
+        node.setSiblingIndex(initialSiblingIndex);
+        
         // console.log("hero load",pos)
         var hv = node.getComponent(HeroViewComp)!;
         const model = this.get(HeroAttrsComp);