feat: Initial release v0.1.0

STP/STEP 3D viewer (WPF, .NET 8) - CADability + HelixToolkit.Wpf:

- Multi-file import (STEP/STL/DXF) with STEP assembly tree
  (per-node visibility/color cascade, zoom-to)
- Measurements: point / distance / edge / face / circle / angle /
  face-to-face distance (B-rep exact where available)
- Assembly verification: two-point align (translate), 3-point align
  (rotate+translate via RigidAlign), axis rotate 90, interference
  check (tri-tri intersection + min gap)
- Section view (CPU mesh clipping, originals preserved)
- mm/inch toggle, CSV export (UTF-8 BOM), 2x PNG screenshot
- Performance: per-file merged edge lines, per-leaf merged mesh in
  browse mode, no BackMaterial on closed solids, edge suspend during
  camera interaction, parallel leaf triangulation with retry
- SmokeTest CLI: import pipeline, --tree, --clip-test,
  --interference-test, --align-test (all passing)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tools/SmokeTest/TreeDump.cs

@@ -0,0 +1,32 @@
+// 實驗工具：印出 STEP 匯入後的物件階層（HierarchyToBlocks=true）
+using CADability;
+using CADability.GeoObject;
+
+namespace SmokeTest;
+
+internal static class TreeDump
+{
+    public static void Run(string path)
+    {
+        var imp = new ImportStep { HierarchyToBlocks = true };
+        GeoObjectList list = imp.Read(path);
+        Console.WriteLine($"top-level objects: {list?.Count}");
+        if (list is null) return;
+        foreach (IGeoObject go in list) Dump(go, 0);
+    }
+
+    private static void Dump(IGeoObject go, int indent)
+    {
+        string name = go switch
+        {
+            Block b => b.Name,
+            Solid s => s.NameOrEmpty,
+            Shell sh => sh.NameOrEmpty,
+            _ => "",
+        };
+        Console.WriteLine($"{new string(' ', indent * 2)}{go.GetType().Name} '{name}' children={go.NumChildren}");
+        if (indent > 6) return;
+        for (int i = 0; i < go.NumChildren; i++)
+            if (go.Child(i) is IGeoObject c) Dump(c, indent + 1);
+    }
+}