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/CardComp.ts

@@ -289,7 +289,7 @@ export class CardComp extends CCComp {
                 cancel: false,
                 reason: "",
                 uuid: this.cardData.uuid,
-                hero_lv: this.cardData.hero_lv ?? 1,
+                hero_lv: smc.getHeroOuterLv(this.cardData.uuid),
                 card_lv: this.cardData.base_card_lv ?? this.cardData.card_lv ?? 1
             };
             oops.message.dispatchEvent(GameEvent.UseHeroCard, guard);
@@ -540,7 +540,7 @@ export class CardComp extends CCComp {
             const heroUuid = isUpgradeCard
                 ? (this.queryHeroUuidByEid(this.cardData!.target_hero_eid as number) ?? this.card_uuid)
                 : this.card_uuid;
-            const heroLv = Math.max(1, this.cardData?.hero_lv ?? 1);
+            const heroLv = Math.max(1, smc.getHeroOuterLv(heroUuid));
             const poolLv = Math.max(1, this.cardData?.base_card_lv ?? this.cardData?.card_lv ?? 1);
             oops.gui.remove(UIID.HInfo);
             oops.gui.open(UIID.HInfo, { heroUuid, heroLv, poolLv });
@@ -756,7 +756,7 @@ export class CardComp extends CCComp {
 
         if (renderType === CardType.Hero) {
             const hero = HeroInfo[renderUuid];
-            const heroLv = Math.max(1, this.cardData.hero_lv ?? hero?.lv ?? 1);
+            const heroLv = Math.max(1, smc.getHeroOuterLv(renderUuid) || hero?.lv || 1);
             this.setLabel(this.name_node, `${hero?.name || ""}`);
             if (this.lvl_node) {
                 // 升级卡：显示「当前→升级后」；普通英雄卡：显示当前等级。统一使用默认颜色