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/Program.cs

@@ -0,0 +1,71 @@
+// 無 UI smoke test：驗證 CAD 檔解析 → 三角化 → 裝配樹 整條匯入管線
+using System.Diagnostics;
+using System.IO;
+using STPViewer.Services;
+
+Console.OutputEncoding = System.Text.Encoding.UTF8;
+
+if (args.Length == 0)
+{
+    Console.WriteLine("用法: SmokeTest [--tree] <file.stp|.stl|.dxf> [...]");
+    return 1;
+}
+
+if (args[0] == "--tree")
+{
+    foreach (string p in args.Skip(1)) SmokeTest.TreeDump.Run(p);
+    return 0;
+}
+
+if (args[0] == "--make-dxf")
+{
+    SmokeTest.MakeDxf.Run(args[1]);
+    return 0;
+}
+
+if (args[0] == "--clip-test")
+    return SmokeTest.ClipTest.Run() == 0 ? 0 : 2;
+
+if (args[0] == "--interference-test")
+    return SmokeTest.InterferenceTest.Run() == 0 ? 0 : 2;
+
+if (args[0] == "--align-test")
+    return SmokeTest.AlignTest.Run() == 0 ? 0 : 2;
+
+var service = new StepImportService { Progress = s => Console.WriteLine($"  [階段] {s}") };
+int failed = 0;
+
+foreach (string path in args)
+{
+    Console.WriteLine($"=== {Path.GetFileName(path)} ===");
+    var sw = Stopwatch.StartNew();
+    try
+    {
+        ImportedFileData data = service.Import(path);
+        sw.Stop();
+        ImportedNode r = data.Root;
+        Console.WriteLine($"  Solids    : {r.SolidCount}");
+        Console.WriteLine($"  Faces     : {r.FaceCount}");
+        Console.WriteLine($"  Triangles : {r.TriangleCount:N0}");
+        Console.WriteLine($"  Bounds    : {r.Bounds.SizeX:F2} x {r.Bounds.SizeY:F2} x {r.Bounds.SizeZ:F2} mm");
+        Console.WriteLine($"  Time      : {sw.ElapsedMilliseconds} ms");
+        Console.WriteLine("  --- 裝配樹 ---");
+        PrintNode(r, 1);
+    }
+    catch (Exception ex)
+    {
+        sw.Stop();
+        failed++;
+        Console.WriteLine($"  FAILED ({sw.ElapsedMilliseconds} ms): {ex.GetType().Name}: {ex.Message}");
+    }
+}
+
+return failed == 0 ? 0 : 2;
+
+static void PrintNode(ImportedNode n, int indent)
+{
+    string seg = n.EdgeSegments is null ? "" : $", edgeSegs={n.EdgeSegments.Count / 2:N0}";
+    Console.WriteLine($"{new string(' ', indent * 2)}{n.Name}  " +
+        $"[solids={n.SolidCount}, faces={n.FaceCount}, tris={n.TriangleCount:N0}{seg}{(n.HasBrep ? "" : ", 無B-rep")}]");
+    foreach (ImportedNode c in n.Children) PrintNode(c, indent + 1);
+}