feat: serialize/deserialize bends in nest file format

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

OpenNest.IO/NestFormat.cs

@@ -50,6 +50,7 @@ namespace OpenNest.IO
             public ConstraintsDto Constraints { get; init; } = new();
             public MaterialDto Material { get; init; } = new();
             public SourceDto Source { get; init; } = new();
+            public List<BendDto> Bends { get; init; } = new();
         }
 
         public record PlateDto
@@ -62,6 +63,7 @@ namespace OpenNest.IO
             public double PartSpacing { get; init; }
             public MaterialDto Material { get; init; } = new();
             public SpacingDto EdgeSpacing { get; init; } = new();
+            public double GrainAngle { get; init; }
             public List<PartDto> Parts { get; init; } = new();
             public List<CutOffDto> CutOffs { get; init; } = new();
         }
@@ -137,6 +139,18 @@ namespace OpenNest.IO
             public double Y { get; init; }
         }
 
+        public record BendDto
+        {
+            public double StartX { get; init; }
+            public double StartY { get; init; }
+            public double EndX { get; init; }
+            public double EndY { get; init; }
+            public string Direction { get; init; } = "Unknown";
+            public double? Angle { get; init; }
+            public double? Radius { get; init; }
+            public string NoteText { get; init; } = "";
+        }
+
         public record BestFitSetDto
         {
             public double PlateWidth { get; init; }

OpenNest.IO/NestReader.cs

@@ -1,3 +1,4 @@
+using OpenNest.Bending;
 using OpenNest.CNC;
 using OpenNest.Engine.BestFit;
 using OpenNest.Geometry;
@@ -91,6 +92,23 @@ namespace OpenNest.IO
                 drawing.Source.Path = d.Source.Path;
                 drawing.Source.Offset = new Vector(d.Source.Offset.X, d.Source.Offset.Y);
 
+                if (d.Bends != null)
+                {
+                    foreach (var b in d.Bends)
+                    {
+                        drawing.Bends.Add(new Bend
+                        {
+                            StartPoint = new Vector(b.StartX, b.StartY),
+                            EndPoint = new Vector(b.EndX, b.EndY),
+                            Direction = Enum.TryParse<BendDirection>(b.Direction, true, out var dir)
+                                ? dir : BendDirection.Unknown,
+                            Angle = b.Angle,
+                            Radius = b.Radius,
+                            NoteText = b.NoteText
+                        });
+                    }
+                }
+
                 if (programs.TryGetValue(d.Id, out var pgm))
                     drawing.Program = pgm;
 
@@ -186,6 +204,7 @@ namespace OpenNest.IO
                 plate.PartSpacing = p.PartSpacing;
                 plate.Material = new Material(p.Material.Name, p.Material.Grade, p.Material.Density);
                 plate.EdgeSpacing = new Spacing(p.EdgeSpacing.Left, p.EdgeSpacing.Bottom, p.EdgeSpacing.Right, p.EdgeSpacing.Top);
+                plate.GrainAngle = p.GrainAngle;
 
                 foreach (var partDto in p.Parts)
                 {

OpenNest.IO/NestWriter.cs

@@ -1,3 +1,4 @@
+using OpenNest.Bending;
 using OpenNest.CNC;
 using OpenNest.Engine.BestFit;
 using System;
@@ -140,7 +141,18 @@ namespace OpenNest.IO
                     {
                         Path = d.Source.Path ?? "",
                         Offset = new OffsetDto { X = d.Source.Offset.X, Y = d.Source.Offset.Y }
-                    }
+                    },
+                    Bends = d.Bends?.Select(b => new BendDto
+                    {
+                        StartX = b.StartPoint.X,
+                        StartY = b.StartPoint.Y,
+                        EndX = b.EndPoint.X,
+                        EndY = b.EndPoint.Y,
+                        Direction = b.Direction.ToString(),
+                        Angle = b.Angle,
+                        Radius = b.Radius,
+                        NoteText = b.NoteText ?? ""
+                    }).ToList() ?? new List<BendDto>()
                 });
             }
             return list;
@@ -200,7 +212,8 @@ namespace OpenNest.IO
                         Bottom = plate.EdgeSpacing.Bottom
                     },
                     Parts = parts,
-                    CutOffs = cutoffs
+                    CutOffs = cutoffs,
+                    GrainAngle = plate.GrainAngle
                 });
             }
             return list;