fix(技能系统): 修复敌方技能施放目标位置计算

添加目标节点存在性检查，防止空引用
重构敌方目标位置计算逻辑，确保在施放范围内

assets/script/game/hero/SCastSystem.ts

@@ -69,8 +69,9 @@ export class SCastSystem extends ecs.ComblockSystem implements ecs.ISystemUpdate
                 if (typeof selfEid !== "number") continue;
                 return { skillId: s_uuid, isFriendly: true, targetPos: null, targetEids: [selfEid] };
             }
-            if (!target) continue;
-            return { skillId: s_uuid, isFriendly: false, targetPos: target.node.position.clone(), targetEids: [] };
+            if (!target || !heroView.node || !target.node) continue;
+            const targetPos = this.buildEnemyCastTargetPos(heroView, target, maxRange);
+            return { skillId: s_uuid, isFriendly: false, targetPos, targetEids: [] };
         }
         return this.emptyCastPlan;
     }
@@ -212,4 +213,11 @@ export class SCastSystem extends ecs.ComblockSystem implements ecs.ISystemUpdate
         if (type === HType.Mid) return 360;
         return this.meleeCastRange;
     }
+
+    private buildEnemyCastTargetPos(caster: HeroViewComp, target: HeroViewComp, castRange: number): Vec3 {
+        const casterPos = caster.node.position;
+        const targetPos = target.node.position;
+        const direction = targetPos.x >= casterPos.x ? 1 : -1;
+        return new Vec3(casterPos.x + direction * castRange, casterPos.y, casterPos.z);
+    }
 }