feat(enemy): 新增 StallDetector 推进停滞检测(+8 单测),为收敛三处重复实现做准备

Assets/Tests/EditMode/Enemies/StallDetectorTests.cs

@@ -0,0 +1,83 @@
+using NUnit.Framework;
+using BaseGames.Enemies;
+
+namespace BaseGames.Tests.EditMode.Enemies
+{
+    /// <summary>
+    /// StallDetector：窗口内净位移不足即判停滞。
+    /// 该逻辑原本在 3 处各写一遍（巡逻 Pace / 导航层 / 冲锋），此处集中钉住行为。
+    /// </summary>
+    public class StallDetectorTests
+    {
+        const float Window = 0.5f, MinProgress = 0.05f;
+
+        [Test]
+        public void BeforeWindowElapses_NeverStalled()
+        {
+            var d = new StallDetector(Window, MinProgress);
+            d.Reset(0f);
+            Assert.IsFalse(d.Tick(0f, 0.1f));   // 完全没动，但窗口未到
+            Assert.IsFalse(d.Tick(0f, 0.1f));
+        }
+
+        [Test]
+        public void NoProgressOverWindow_Stalled()
+        {
+            var d = new StallDetector(Window, MinProgress);
+            d.Reset(0f);
+            Assert.IsFalse(d.Tick(0f, 0.4f));
+            Assert.IsTrue (d.Tick(0f, 0.2f));   // 累计 0.6s ≥ 窗口，净位移 0
+        }
+
+        [Test]
+        public void EnoughProgressOverWindow_NotStalled()
+        {
+            var d = new StallDetector(Window, MinProgress);
+            d.Reset(0f);
+            Assert.IsFalse(d.Tick(1f, 0.6f));   // 位移 1m 远超阈值
+        }
+
+        [Test]
+        public void ProgressJustBelowThreshold_Stalled()
+        {
+            var d = new StallDetector(Window, MinProgress);
+            d.Reset(0f);
+            Assert.IsTrue(d.Tick(0.04f, 0.6f)); // 0.04 < 0.05
+        }
+
+        [Test]
+        public void ProgressCountsBothDirections()
+        {
+            var d = new StallDetector(Window, MinProgress);
+            d.Reset(0f);
+            Assert.IsFalse(d.Tick(-1f, 0.6f));  // 向左移动同样算推进
+        }
+
+        [Test]
+        public void AfterStalled_WindowRestartsFromCurrentPosition()
+        {
+            var d = new StallDetector(Window, MinProgress);
+            d.Reset(0f);
+            Assert.IsTrue (d.Tick(0f, 0.6f));   // 第一次判停滞
+            Assert.IsFalse(d.Tick(0f, 0.1f));  // 窗口已重开，未到期
+            Assert.IsTrue (d.Tick(0f, 0.6f));  // 再次到期且仍无推进
+        }
+
+        [Test]
+        public void Reset_ClearsAccumulatedTime()
+        {
+            var d = new StallDetector(Window, MinProgress);
+            d.Reset(0f);
+            d.Tick(0f, 0.4f);
+            d.Reset(0f);                        // 重开窗口
+            Assert.IsFalse(d.Tick(0f, 0.2f));  // 只累计了 0.2s
+        }
+
+        [Test]
+        public void WithoutReset_FirstTickInitializes()
+        {
+            var d = new StallDetector(Window, MinProgress);
+            Assert.IsFalse(d.Tick(5f, 1f));     // 未 Reset 时首帧只做初始化，不误判
+        }
+    }
+}

Assets/_Game/Scripts/Enemies/StallDetector.cs

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+using UnityEngine;
+
+namespace BaseGames.Enemies
+{
+    /// <summary>
+    /// 推进停滞检测：滑动窗口内的**净水平位移**不足阈值即判为停滞。
+    /// 用于"命令了移动却推不动"的兜底（撞上未纳入检测层的碰撞体、贴墙微抖等）。
+    ///
+    /// <para>用净位移而非逐帧差值，避免"贴墙推进-被弹回"的微抖每帧重置计数。</para>
+    /// <para><b>调用方须以字段持有本结构</b>（struct 的方法会就地修改字段）；
+    /// 开始移动 / 更换目标后调用 <see cref="Reset"/> 重开窗口。</para>
+    /// </summary>
+    public struct StallDetector
+    {
+        private readonly float _windowSeconds;
+        private readonly float _minProgress;
+        private float _timer;
+        private float _startX;
+        private bool  _initialized;
+
+        /// <param name="windowSeconds">判定窗口时长（秒）。</param>
+        /// <param name="minProgress">窗口内所需的最小净位移（米）。</param>
+        public StallDetector(float windowSeconds, float minProgress)
+        {
+            _windowSeconds = windowSeconds;
+            _minProgress   = minProgress;
+            _timer         = 0f;
+            _startX        = 0f;
+            _initialized   = false;
+        }
+
+        /// <summary>以当前位置重开窗口。</summary>
+        public void Reset(float currentX)
+        {
+            _startX      = currentX;
+            _timer       = 0f;
+            _initialized = true;
+        }
+
+        /// <summary>
+        /// 推进一帧。返回 true 表示本窗口内推进不足（停滞）；返回 true 后窗口自动以当前位置重开。
+        /// </summary>
+        public bool Tick(float currentX, float deltaTime)
+        {
+            if (!_initialized) { Reset(currentX); return false; }
+
+            _timer += deltaTime;
+            if (_timer < _windowSeconds) return false;
+
+            bool stalled = Mathf.Abs(currentX - _startX) < _minProgress;
+            _startX = currentX;
+            _timer  = 0f;
+            return stalled;
+        }
+    }
+}