feat(skill-system): 新增计时debuff机制，支持技能命中敌方附加减益效果

本次提交完整实现了技能对敌附加debuff的完整流程：
1.  新增TimedDebuffSnapshot数据结构，用于透传debuff配置
2.  在SkillConfig和SkillOverrides中新增debuff相关配置项
3.  实现HeroAtkSystem中debuff的判定与施加逻辑
4.  完善后台配置、前端编辑器的debuff配置支持
5.  调整了buff目标判定逻辑，修复了原有默认目标的语义混淆问题
6.  优化了BuffSystem的调试日志，新增了debuff分类标识
7.  批量更新了现有英雄技能的debuff配置示例

assets/script/game/hero/SCastSystem.ts

@@ -2,7 +2,7 @@ import { ecs } from "../../../../extensions/oops-plugin-framework/assets/libs/ec
 import { Vec3, Prefab, instantiate, tween, Node } from "cc";
 import { HeroAttrsComp } from "./HeroAttrsComp";
 import { HeroViewComp } from "./HeroViewComp";
-import { DTType, RType, SkillConfig, SkillKind, SkillSet, TGroup, SkillOverrides, mergeSkillParams, BuffTarget } from "../common/config/SkillSet";
+import { DTType, RType, SkillConfig, SkillKind, SkillSet, TGroup, SkillOverrides, mergeSkillParams } from "../common/config/SkillSet";
 import { Skill } from "../skill/Skill";
 import { SkillView } from "../skill/SkillView";
 import { smc } from "../common/SingletonModuleComp";
@@ -556,8 +556,7 @@ 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
-            // buff_target=Enemy 时 timed_buff_id 已在 applyFriendlySkillEffects 入口分流到敌方网格，此处跳过避免误挂友方
-            if (config.timed_buff_id && config.buff_target !== BuffTarget.Enemy) {
+            if (config.timed_buff_id) {
                 // 汇总 buff 覆写参数：value 覆写修饰数值，duration 覆写持续时间
                 const buffOverrides: { value?: number; duration?: number } = {};
                 if (config.buff_value !== undefined) buffOverrides.value = config.buff_value;