feat: add EdgeStartSequencer

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

OpenNest.Engine/Sequencing/EdgeStartSequencer.cs

@@ -0,0 +1,36 @@
+using System.Collections.Generic;
+using System.Linq;
+
+namespace OpenNest.Engine.Sequencing
+{
+    public class EdgeStartSequencer : IPartSequencer
+    {
+        public List<SequencedPart> Sequence(IReadOnlyList<Part> parts, Plate plate)
+        {
+            // Plate(width, length) stores Size with Width/Length swapped internally.
+            // Reconstruct the logical plate box using the BoundingBox origin and the
+            // corrected extents: Size.Length = X-extent, Size.Width = Y-extent.
+            var origin = plate.BoundingBox(false);
+            var plateBox = new OpenNest.Geometry.Box(
+                origin.X, origin.Y,
+                plate.Size.Length,
+                plate.Size.Width);
+
+            return parts
+                .OrderBy(p => MinEdgeDistance(p.BoundingBox.Center, plateBox))
+                .ThenBy(p => p.Location.X)
+                .Select(p => new SequencedPart { Part = p })
+                .ToList();
+        }
+
+        private static double MinEdgeDistance(OpenNest.Geometry.Vector center, OpenNest.Geometry.Box plateBox)
+        {
+            var distLeft   = center.X - plateBox.Left;
+            var distRight  = plateBox.Right - center.X;
+            var distBottom = center.Y - plateBox.Bottom;
+            var distTop    = plateBox.Top - center.Y;
+
+            return System.Math.Min(System.Math.Min(distLeft, distRight), System.Math.Min(distBottom, distTop));
+        }
+    }
+}