docs: document smoothing processing core

ClumsyPilot/ParkrobTrajplanner/PathSmoothing/LocalG2/LocalG2SmoothingRegion.cs

@@ -8,6 +8,12 @@ namespace MultiWheelC.TrajectoryPlanning.PathSmoothing.LocalG2;
 /// <summary>一个局部 G2 候选可替换的弧长窗口。</summary>
 internal sealed class LocalG2WindowVariant
 {
+    /// <summary>创建同一平滑区域内一个可尝试替换的弧长窗口变体。</summary>
+    /// <param name="candidateIndex">区域内候选的稳定从零开始索引。</param>
+    /// <param name="startArcLengthMeters">窗口起点弧长，单位 m。</param>
+    /// <param name="endArcLengthMeters">窗口终点弧长，单位 m。</param>
+    /// <param name="leftWindowLengthMeters">过渡点左侧窗口长度，单位 m。</param>
+    /// <param name="rightWindowLengthMeters">过渡点右侧窗口长度，单位 m。</param>
     internal LocalG2WindowVariant(int candidateIndex, double startArcLengthMeters, double endArcLengthMeters,
         double leftWindowLengthMeters, double rightWindowLengthMeters)
     {
@@ -33,6 +39,12 @@ internal sealed class LocalG2WindowVariant
 /// <summary>至少存在一个联合合法生成窗口变体的一组曲率过渡。</summary>
 internal sealed class LocalG2SmoothingRegion
 {
+    /// <summary>创建一个包含共同可用窗口变体的局部曲率过渡区域。</summary>
+    /// <param name="segmentIndex">所属方向段在预处理路径中的从零开始索引。</param>
+    /// <param name="transitions">归并到该区域的曲率跳变集合。</param>
+    /// <param name="maximumStartArcLengthMeters">所有候选允许的最晚窗口起点，单位 m。</param>
+    /// <param name="maximumEndArcLengthMeters">所有候选允许的最早窗口终点，单位 m。</param>
+    /// <param name="windowVariants">至少一个合法的窗口变体集合。</param>
     internal LocalG2SmoothingRegion(
         int segmentIndex,
         IReadOnlyList<CurvatureTransition> transitions,