feat: add PartSequencerFactory

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

OpenNest.Engine/Sequencing/PartSequencerFactory.cs

@@ -0,0 +1,23 @@
+using System;
+using OpenNest.CNC.CuttingStrategy;
+
+namespace OpenNest.Engine.Sequencing
+{
+    public static class PartSequencerFactory
+    {
+        public static IPartSequencer Create(SequenceParameters parameters)
+        {
+            return parameters.Method switch
+            {
+                SequenceMethod.RightSide  => new RightSideSequencer(),
+                SequenceMethod.LeftSide   => new LeftSideSequencer(),
+                SequenceMethod.BottomSide => new BottomSideSequencer(),
+                SequenceMethod.EdgeStart  => new EdgeStartSequencer(),
+                SequenceMethod.LeastCode  => new LeastCodeSequencer(),
+                SequenceMethod.Advanced   => new AdvancedSequencer(parameters),
+                _ => throw new NotSupportedException(
+                    $"Sequence method '{parameters.Method}' is not supported.")
+            };
+        }
+    }
+}

OpenNest.Tests/Sequencing/PartSequencerFactoryTests.cs

@@ -0,0 +1,30 @@
+using System;
+using OpenNest.CNC.CuttingStrategy;
+using OpenNest.Engine.Sequencing;
+using Xunit;
+
+namespace OpenNest.Tests.Sequencing;
+
+public class PartSequencerFactoryTests
+{
+    [Theory]
+    [InlineData(SequenceMethod.RightSide, typeof(RightSideSequencer))]
+    [InlineData(SequenceMethod.LeftSide, typeof(LeftSideSequencer))]
+    [InlineData(SequenceMethod.BottomSide, typeof(BottomSideSequencer))]
+    [InlineData(SequenceMethod.EdgeStart, typeof(EdgeStartSequencer))]
+    [InlineData(SequenceMethod.LeastCode, typeof(LeastCodeSequencer))]
+    [InlineData(SequenceMethod.Advanced, typeof(AdvancedSequencer))]
+    public void Create_ReturnsCorrectType(SequenceMethod method, Type expectedType)
+    {
+        var parameters = new SequenceParameters { Method = method };
+        var sequencer = PartSequencerFactory.Create(parameters);
+        Assert.IsType(expectedType, sequencer);
+    }
+
+    [Fact]
+    public void Create_RightSideAlt_Throws()
+    {
+        var parameters = new SequenceParameters { Method = SequenceMethod.RightSideAlt };
+        Assert.Throws<NotSupportedException>(() => PartSequencerFactory.Create(parameters));
+    }
+}