feat(enemy): 目标点吸附统一处理导航宽度,Waypoint 不再卡崖边

将"角色导航宽度"收口到导航执行层单一入口,意图层(Locomotion/AI)只递原始目标、不再感知身体尺寸:

- NavAgent 新增 TryGetStandablePointNear:把世界点映射到最近可行走段并按 endMargin 内缩两端(与 SetRandomDestinationOnCurrentSegment 同源)
- EnemyNavAgent 新增 ResolveStandablePoint,以 EnemyMovement.EdgeSafeMargin(半宽+落崖余量)为唯一宽度真源;加 _goalMapSearchRadius
- IPathAgent 暴露 ResolveStandablePoint;FlyingDirectNavigator 原样返回(飞行无崖沿约束),NullPathAgent 空实现
- EnemyLocomotion Waypoint 分支改用吸附后的可达点做移动与到达判定,修复路点摆在空中/崖外时永不到达而卡死;吸附失败显式报错暴露误配,不静默兜底

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Assets/_Game/Scripts/Enemies/Navigation/EnemyNavAgent.cs

@@ -35,6 +35,10 @@ namespace BaseGames.Enemies.Navigation
         [Tooltip("两次重算最小间隔(s)：留出跨帧路径计算完成的时间")]
         [SerializeField] private float _repathMinInterval     = 0.25f;
 
+        [Header("目标点吸附")]
+        [Tooltip("把巡逻/移动目标映射到最近可行走段时允许的最大偏离(m)；超出视为无效目标(路点摆得离导航面太远)")]
+        [SerializeField] private float _goalMapSearchRadius    = 2f;
+
         // 重寻路防抖状态
         private Vector2 _lastPathGoal;
         private bool    _hasPathGoal;
@@ -176,6 +180,16 @@ namespace BaseGames.Enemies.Navigation
             => _navAgent?.SetRandomDestinationOnCurrentSegment(
                    _enemyMovement != null ? _enemyMovement.EdgeSafeMargin : 0f) ?? false;
 
+        // 目标点吸附：把任意世界目标映射到最近可行走段、并按身体宽度(EdgeSafeMargin)从段两端内缩，
+        // 得到"身体真正站得住"的点。身体宽度是本执行层独占的知识——意图层(AI/Locomotion)只递原始目标。
+        // 映射不到任何段(目标离导航面太远)时返回 false，standable 回落为原始 target。
+        public bool ResolveStandablePoint(Vector2 target, out Vector2 standable)
+        {
+            if (_navAgent == null) { standable = target; return false; }
+            float margin = _enemyMovement != null ? _enemyMovement.EdgeSafeMargin : 0f;
+            return _navAgent.TryGetStandablePointNear(target, _goalMapSearchRadius, margin, out standable);
+        }
+
         public bool IsNearEdge()
         {
             var origin = (Vector2)transform.position;