feat(skill): add timed buff support for skills

1. 新增timed_buff_id配置项到SkillConfig和SkillOverrides接口
2. 实现计时buff逻辑：配置该id时通过buffManager添加限时buff，跳过永久buff逻辑
3. 优化代码格式和空行规范，修复部分代码细节问题

assets/script/game/common/config/SkillSet.ts

@@ -154,6 +154,7 @@ export interface SkillConfig {
     stun?: number,             // 额外击晕概率
     bck?: number,              // 额外击退概率
     buff_type?: Attrs,         // Buff 类型 (单一职责)
+    timed_buff_id?: number,    // 计时性 buff 配置 id（指向 BuffList），存在时走 buffManager 而非永久 add_*
     call_hero?: number,            // 召唤技能召唤英雄id(可选)
     is_accel?: boolean,            // 是否逐渐加速飞行
     info: string,              // 技能描述
@@ -170,6 +171,7 @@ export interface SkillOverrides {
     stun?: number;
     bck?: number;
     buff_type?: Attrs;
+    timed_buff_id?: number;
     call_hero?: number;
     is_accel?: boolean;
 }

assets/script/game/hero/SCastSystem.ts

@@ -14,6 +14,7 @@ import { SkillTriggerType } from "../common/config/heroSet";
 import { SkillTriggerHelper } from "./SkillTriggerHelper";
 import { MissionEconomy } from "../map/MissionEconomy";
 import { MissionHeroComp } from "../map/MissionHeroComp";
+import { buffManager } from "./BuffManager";
 
 /**
  * ==================== 自动施法系统 ====================
@@ -485,6 +486,18 @@ export class SCastSystem extends ecs.ComblockSystem implements ecs.ISystemUpdate
         }
 
         if (config.buff_type !== undefined) {
+            // 计时性 buff：配置了 timed_buff_id 时走 buffManager 限时路径，
+            // 同一技能不应既永久加成又限时加成，故提前 return 跳过下方永久 add_* 逻辑
+            if (config.timed_buff_id) {
+                buffManager.applyBuff(
+                    target.ent,
+                    config.timed_buff_id,
+                    _cAttrsComp.hero_uuid,
+                    _cAttrsComp.ap
+                );
+                return;
+            }
+
             const baseValue = config.ap;
             let upgradeValue = 0;