feat: 实现英雄局外成长系统

1. 新增GameEvent事件枚举HERO_GROWTH_UPDATE
2. 新增英雄局外升级所需碎片配置表
3. 新增英雄局外成长数据持久化与相关工具方法
4. 重构英雄卡片等级逻辑，统一使用局外成长等级
5. 更新英雄设计文档与相关注释

assets/script/game/map/CardLiteComp.ts

@@ -132,7 +132,7 @@ export class CardLiteComp extends CCComp {
                 weight: 25,
                 card_lv: cardLv,
                 kind: CKind.Hero,
-                hero_lv: hero.lv || 1
+                hero_lv: smc.getHeroOuterLv(hero.uuid)
             });
         }
     }
@@ -231,7 +231,7 @@ export class CardLiteComp extends CCComp {
 
         if (this.card_type === CardType.Hero) {
             const hero = HeroInfo[this.card_uuid];
-            const heroLv = Math.max(1, this.cardData.hero_lv ?? hero?.lv ?? 1);
+            const heroLv = Math.max(1, smc.getHeroOuterLv(this.card_uuid) || hero?.lv || 1);
             this.setLabel(this.name_node, `${hero?.name || ""}`);
             if (this.lvl_node) {
                 this.lvl_node.string = `Lv.${heroLv}`;