feat(hero/skill): add skill level override resolution logic

1. 新增resolveSkillOverrides工具函数实现技能等级分档覆盖逻辑
2. 为所有英雄/怪物技能模块添加运行时overrides分档处理
3. 扩展技能描述系统以展示分档后的技能等级
4. 新增技能分档配置类型定义与注释

assets/script/game/map/HeroBoxComp.ts

@@ -214,6 +214,7 @@ export class HeroBoxComp extends CCComp {
 
         const buildSource = (lv: number): ISkillDescSource => ({
             lv: lv,
+            skills: hero.skills,
             call: hero.call,
             dead: hero.dead,
             fstart: hero.fstart,