feat(world): 检查点复活位置由 RespawnPoint 子节点显式配置

CheckpointMarker 新增 _respawnPoint 引用，注册的检查点位置改为
该子节点的位置——触发区与出生点解耦，触发区可横跨通道、出生点
精确落在安全平台上。漏配时 Awake 显式报错且不注册（不以标记
自身位置兜底）。Gizmos 增画复活点（青色）与触发区连线，漏配
画红叉警示。PlaceCheckpointMarker 脚手架自动创建并绑定
RespawnPoint 子节点。

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Assets/_Game/Scripts/World/CheckpointMarker.cs

@@ -13,6 +13,8 @@ namespace BaseGames.World
     ///   - 激活状态仅存于运行时，不持久化，换房间后重置
     ///   - 闩锁按接触周期：进入时注册并广播一次，离开触发区后重置，
     ///     同一次接触内不重复结算
+    ///   - 触发区与出生位置解耦：注册的是 _respawnPoint 子节点的位置，
+    ///     触发区可横跨通道，出生点精确落在安全平台上
     /// </summary>
     [RequireComponent(typeof(Collider2D))]
     public class CheckpointMarker : MonoBehaviour
@@ -21,6 +23,10 @@ namespace BaseGames.World
         [Tooltip("勾选 Player 层")]
         [SerializeField] private LayerMask _playerLayers;
 
+        [Header("复活点")]
+        [Tooltip("玩家回溯时出现的位置（必配，脚手架自动创建 RespawnPoint 子节点）")]
+        [SerializeField] private Transform _respawnPoint;
+
         [Header("事件")]
         [Tooltip("EVT_CheckpointReached — 激活时广播，供 VFX/SFX 使用")]
         [SerializeField] private VoidEventChannelSO _onCheckpointReached;
@@ -38,15 +44,20 @@ namespace BaseGames.World
                 col.isTrigger = true;
                 Debug.LogWarning($"[CheckpointMarker] {name}: Collider2D.isTrigger 已自动设为 true。", this);
             }
+
+            if (_respawnPoint == null)
+                Debug.LogError($"[CheckpointMarker] {name}: _respawnPoint 未绑定，检查点无法注册。" +
+                               "请用脚手架（BaseGames/Scene/Place/Checkpoint Marker）创建，或手动补 RespawnPoint 子节点并绑定。", this);
         }
 
         private void OnTriggerEnter2D(Collider2D other)
         {
             if (_isActivated) return;
             if ((_playerLayers.value & (1 << other.gameObject.layer)) == 0) return;
+            if (_respawnPoint == null) return; // 漏配已在 Awake 报错，此处不以标记自身位置兜底
 
             _isActivated = true;
-            ServiceLocator.GetOrDefault<ICheckpointService>()?.RegisterCheckpoint(transform.position);
+            ServiceLocator.GetOrDefault<ICheckpointService>()?.RegisterCheckpoint(_respawnPoint.position);
             _onCheckpointReached?.Raise();
         }
 
@@ -64,6 +75,23 @@ namespace BaseGames.World
             Gizmos.DrawWireSphere(transform.position, 0.4f);
             Gizmos.DrawLine(transform.position + Vector3.down * 0.4f,
                             transform.position + Vector3.up   * 0.8f);
+
+            // 复活点：青色小球 + 落点竖线 + 与触发区的连线；漏配画红叉警示
+            if (_respawnPoint != null)
+            {
+                Gizmos.color = new Color(0f, 0.8f, 1f, 0.9f);
+                Gizmos.DrawWireSphere(_respawnPoint.position, 0.25f);
+                Gizmos.DrawLine(_respawnPoint.position + Vector3.down * 0.5f,
+                                _respawnPoint.position + Vector3.up   * 0.5f);
+                Gizmos.color = new Color(0f, 0.8f, 1f, 0.4f);
+                Gizmos.DrawLine(transform.position, _respawnPoint.position);
+            }
+            else
+            {
+                Gizmos.color = Color.red;
+                Gizmos.DrawLine(transform.position + new Vector3(-0.3f, -0.3f), transform.position + new Vector3(0.3f, 0.3f));
+                Gizmos.DrawLine(transform.position + new Vector3(-0.3f, 0.3f),  transform.position + new Vector3(0.3f, -0.3f));
+            }
         }
     }
 }