多轮审查和修复

Assets/Scripts/World/BreadcrumbTracker.cs

@@ -0,0 +1,61 @@
+using System.Collections.Generic;
+using UnityEngine;
+
+namespace BaseGames.World
+{
+    /// <summary>
+    /// 玩家面包屑轨迹追踪器（架构 21_LiquidPuzzleModule §15）。
+    /// 每 RecordInterval 秒记录一次玩家位置（仅当移动距离超过 MinMoveDistance 时）。
+    /// 最多保存 MaxCrumbs 个历史位置，超出后移除最旧的。
+    /// </summary>
+    public class BreadcrumbTracker : MonoBehaviour
+    {
+        [SerializeField, Min(0.1f)] private float _recordInterval  = 2f;
+        [SerializeField, Min(1)]    private int   _maxCrumbs       = 20;
+        [SerializeField, Min(0.1f)] private float _minMoveDistance = 1f;
+
+        private readonly Queue<Vector2> _crumbs     = new();
+        private Vector2                 _lastPos;
+        private float                   _timer;
+
+        private Transform _playerTransform;
+
+        // ── Unity 生命周期 ────────────────────────────────────────────────
+        private void Awake()
+        {
+            var go = GameObject.FindWithTag("Player");
+            if (go != null) _playerTransform = go.transform;
+        }
+
+        private void Update()
+        {
+            if (_playerTransform == null) return;
+
+            _timer += Time.deltaTime;
+            if (_timer < _recordInterval) return;
+            _timer = 0f;
+
+            Vector2 pos = _playerTransform.position;
+            if (_crumbs.Count > 0 && Vector2.Distance(pos, _lastPos) < _minMoveDistance)
+                return;
+
+            _crumbs.Enqueue(pos);
+            _lastPos = pos;
+
+            while (_crumbs.Count > _maxCrumbs)
+                _crumbs.Dequeue();
+        }
+
+        // ── 公共 API ──────────────────────────────────────────────────────
+        /// <summary>返回最近 count 个面包屑位置（从旧到新排列）。</summary>
+        public IReadOnlyList<Vector2> GetRecentCrumbs(int count)
+        {
+            var result = new List<Vector2>(_crumbs);
+            if (result.Count <= count) return result;
+            return result.GetRange(result.Count - count, count);
+        }
+
+        /// <summary>清空全部轨迹记录（如死亡后重生时调用）。</summary>
+        public void Clear() => _crumbs.Clear();
+    }
+}