feat: 添加击退效果相关逻辑

1. 新增击退概率、击退距离、击退抗性属性配置
2. 实现击退判定与击退位移逻辑，整合进受击流程
3. 重构后退方法支持自定义击退距离参数

assets/script/game/hero/HeroAttrsComp.ts

@@ -43,6 +43,9 @@ export class HeroAttrsComp extends ecs.Comp {
     // ==================== 特殊属性 ====================
     critical: number = 0;       // 暴击率
     freeze_chance: number = 0;  // 冰冻概率
+    knockback_chance: number = 0; // 击退概率
+    knockback_distance: number = 0; // 击退距离强化
+    knockback_res: number = 0; // 击退抗性
     crit_damage: number = 0;    // 额外暴击伤害
     puncture: number = 0;       // 穿刺次数
     wfuny: number = 0;          // 风怒
@@ -297,6 +300,9 @@ export class HeroAttrsComp extends ecs.Comp {
         this.revive = undefined;
         this.critical = 0;
         this.freeze_chance = 0;
+        this.knockback_chance = 0;
+        this.knockback_distance = 0;
+        this.knockback_res = 0;
         this.crit_damage = 0;
         this.revived_count = 0;
         this.invincible_time = 0;