refactor: 移除战斗结束相关的FEnd触发逻辑

此次提交全面清理了所有与战斗结束（FEnd）相关的代码：
1. 移除了Hero、Monster等实体中的fend属性与运行时处理
2. 删除了SkillTriggerHelper中的FEnd触发分支
3. 移除了GameEvent中的FightEnd事件与相关监听
4. 清理了配置文件中的FEnd相关枚举、字段与装备
5. 重构了MissionComp的回合逻辑，不再触发战后技能
6. 更新了注释与文档，移除过时的FEnd相关说明

彻底移除了已不再使用的战斗结束触发机制，简化了代码架构。

assets/script/game/hero/HeroAttrsComp.ts

@@ -47,7 +47,6 @@ export class HeroAttrsComp extends ecs.Comp {
     [SkillTriggerType.Call]?: TriggerGrouped;
     [SkillTriggerType.Dead]?: TriggerGrouped;
     [SkillTriggerType.FStart]?: TriggerGrouped;
-    [SkillTriggerType.FEnd]?: TriggerGrouped;
     [SkillTriggerType.Atking]?: TriggerGrouped;
     [SkillTriggerType.Atked]?: TriggerGrouped;
     /** 驻场光环（按 lv 解锁，存活期间全局生效） */
@@ -68,8 +67,6 @@ export class HeroAttrsComp extends ecs.Comp {
     runtime_dead?: { s_uuid: number; t_num: number; overrides?: SkillOverrides }[];
     /** 当前等级下生效的战前触发条目 */
     runtime_fstart?: { s_uuid: number; t_num: number; overrides?: SkillOverrides }[];
-    /** 当前等级下生效的战后触发条目 */
-    runtime_fend?: { s_uuid: number; t_num: number; overrides?: SkillOverrides }[];
     /** 当前等级下生效的驻场光环词条列表 */
     runtime_field?: FieldEntry[];
     /** 当前等级下生效的复活配置 */
@@ -580,7 +577,6 @@ export class HeroAttrsComp extends ecs.Comp {
         this.call = undefined;
         this.dead = undefined;
         this.fstart = undefined;
-        this.fend = undefined;
         this.atking = undefined;
         this.atked = undefined;
         this.field = undefined;
@@ -592,7 +588,6 @@ export class HeroAttrsComp extends ecs.Comp {
         this.runtime_call = undefined;
         this.runtime_dead = undefined;
         this.runtime_fstart = undefined;
-        this.runtime_fend = undefined;
         this.runtime_field = undefined;
         this.runtime_revive = undefined;
         this.critical = 0;