fix cubetree init crash.

App/wwwroot/HiAPI-docsite/api/Hi.Geom.Cylindroid.html

@@ -6,7 +6,7 @@
       <meta name="viewport" content="width=device-width, initial-scale=1.0">
       <meta name="title" content="Class Cylindroid | HiAPI-C# 2025 ">
       
-      <meta name="description" content="Geometry of Cylindroid.">
+      <meta name="description" content="3d Geometry of Cylindroid.">
       <link rel="icon" href="../img/HiAPI.favicon.ico">
       <link rel="stylesheet" href="../public/docfx.min.css">
       <link rel="stylesheet" href="../public/main.css">
@@ -97,7 +97,7 @@ Class Cylindroid
   <dl><dt>Assembly</dt><dd>HiGeom.dll</dd></dl>
   </div>
 
-  <div class="markdown summary"><p>Geometry of Cylindroid.</p>
+  <div class="markdown summary"><p>3d Geometry of Cylindroid.</p>
 </div>
   <div class="markdown conceptual"></div>