fix(console): give the DXF-only plate a quantity of 1

LoadOrCreateNest built the DXF-only plate with `new Plate`, leaving
Quantity at 0, so results reported "Parts placed: 0" and 0% weighted
utilization, and drawings' nested quantities stayed at zero. Build it
through Nest.CreatePlate as the desktop does.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

OpenNest.Console/Program.cs

@@ -372,9 +372,11 @@ static class NestConsole
             return null;
         }
 
+        // Build the plate as the desktop does: Quantity = 1 so part counts and the
+        // drawings' nested quantities include it.
         var newNest = new Nest { Name = "DXF Import" };
-        var plate = new Plate { Size = options.PlateSize.Value };
-        newNest.Plates.Add(plate);
+        newNest.PlateDefaults.Size = options.PlateSize.Value;
+        newNest.CreatePlate();
 
         foreach (var dxf in dxfFiles)
         {

OpenNest.FrontEnd.Tests/NestingPipelineTests.cs

@@ -326,6 +326,20 @@ public class NestingPipelineTests : IDisposable
         Assert.False(File.Exists(output));
     }
 
+    [Fact]
+    public void Console_DxfOnlyFillCountsPlacedPartsOnASingleSheet()
+    {
+        var input = Path.Combine(directory, "square.dxf");
+        var output = Path.Combine(directory, "output.nest");
+        Dxf.ExportProgram(Square().Program, input);
+        Assert.Equal(0, RunConsole(input, "--size", "20x30", "--quantity", "6", "--output", output));
+        var nest = new NestReader(output).Read();
+        var plate = nest.Plates.Single();
+        Assert.Equal(1, plate.Quantity);
+        Assert.Equal(6, plate.Parts.Count);
+        Assert.Equal(plate.Parts.Count, nest.Drawings.Single().Quantity.Nested);
+    }
+
     private NestRequest Request(string engine)
     {
         var path = Path.Combine(directory, "square.dxf");