feat: add ApplyLeadIns/RemoveLeadIns to Part with CuttingParameters storage

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

OpenNest.Tests/PartLeadInTests.cs

@@ -0,0 +1,127 @@
+using OpenNest.CNC;
+using OpenNest.CNC.CuttingStrategy;
+using OpenNest.Geometry;
+
+namespace OpenNest.Tests;
+
+public class PartLeadInTests
+{
+    private static Part MakeSquarePart()
+    {
+        var pgm = new Program();
+        pgm.Codes.Add(new RapidMove(new Vector(0, 0)));
+        pgm.Codes.Add(new LinearMove(new Vector(0, 10)));
+        pgm.Codes.Add(new LinearMove(new Vector(10, 10)));
+        pgm.Codes.Add(new LinearMove(new Vector(10, 0)));
+        pgm.Codes.Add(new LinearMove(new Vector(0, 0)));
+        var drawing = new Drawing("test", pgm);
+        return new Part(drawing);
+    }
+
+    [Fact]
+    public void ApplyLeadIns_SetsHasManualLeadIns()
+    {
+        var part = MakeSquarePart();
+        var parameters = new CuttingParameters
+        {
+            ExternalLeadIn = new LineLeadIn { Length = 0.5, ApproachAngle = 90 },
+            InternalLeadIn = new LineLeadIn { Length = 0.25, ApproachAngle = 90 }
+        };
+
+        part.ApplyLeadIns(parameters, new Vector(-5, -5));
+
+        Assert.True(part.HasManualLeadIns);
+    }
+
+    [Fact]
+    public void ApplyLeadIns_StoresCuttingParameters()
+    {
+        var part = MakeSquarePart();
+        var parameters = new CuttingParameters
+        {
+            ExternalLeadIn = new LineLeadIn { Length = 0.5, ApproachAngle = 90 },
+            InternalLeadIn = new LineLeadIn { Length = 0.25, ApproachAngle = 90 }
+        };
+
+        part.ApplyLeadIns(parameters, new Vector(-5, -5));
+
+        Assert.Same(parameters, part.CuttingParameters);
+    }
+
+    [Fact]
+    public void ApplyLeadIns_ProgramContainsLeadinCodes()
+    {
+        var part = MakeSquarePart();
+        var parameters = new CuttingParameters
+        {
+            ExternalLeadIn = new LineLeadIn { Length = 0.5, ApproachAngle = 90 }
+        };
+
+        part.ApplyLeadIns(parameters, new Vector(-5, -5));
+
+        var hasLeadin = part.Program.Codes.OfType<LinearMove>().Any(m => m.Layer == LayerType.Leadin);
+        Assert.True(hasLeadin);
+    }
+
+    [Fact]
+    public void RemoveLeadIns_RestoresOriginalProgram()
+    {
+        var part = MakeSquarePart();
+        var originalCodeCount = part.Program.Codes.Count;
+        var parameters = new CuttingParameters
+        {
+            ExternalLeadIn = new LineLeadIn { Length = 0.5, ApproachAngle = 90 }
+        };
+
+        part.ApplyLeadIns(parameters, new Vector(-5, -5));
+        part.RemoveLeadIns();
+
+        Assert.False(part.HasManualLeadIns);
+        Assert.Null(part.CuttingParameters);
+        Assert.Equal(originalCodeCount, part.Program.Codes.Count);
+    }
+
+    [Fact]
+    public void RemoveLeadIns_PreservesRotation()
+    {
+        var part = MakeSquarePart();
+        part.Rotate(System.Math.PI / 4); // 45 degrees
+        var rotation = part.Rotation;
+
+        var parameters = new CuttingParameters
+        {
+            ExternalLeadIn = new LineLeadIn { Length = 0.5, ApproachAngle = 90 }
+        };
+
+        part.ApplyLeadIns(parameters, new Vector(-5, -5));
+        part.RemoveLeadIns();
+
+        Assert.Equal(rotation, part.Rotation, 6);
+    }
+
+    [Fact]
+    public void RemoveLeadIns_PreservesLocation()
+    {
+        var part = MakeSquarePart();
+        part.Offset(20, 30);
+        var location = part.Location;
+
+        var parameters = new CuttingParameters
+        {
+            ExternalLeadIn = new LineLeadIn { Length = 0.5, ApproachAngle = 90 }
+        };
+
+        part.ApplyLeadIns(parameters, new Vector(-5, -5));
+        part.RemoveLeadIns();
+
+        Assert.Equal(location.X, part.Location.X, 6);
+        Assert.Equal(location.Y, part.Location.Y, 6);
+    }
+
+    [Fact]
+    public void LeadInsLocked_DefaultsFalse()
+    {
+        var part = MakeSquarePart();
+        Assert.False(part.LeadInsLocked);
+    }
+}