feat(ui): add ColorScheme.Name/PartColors instance props and JSON serializer

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

OpenNest/ColorScheme.cs

@@ -13,10 +13,13 @@ namespace OpenNest
         private Color edgeSpacingColor;
         private Color previewPartColor;
 
-        public static Color[] PartColors => Drawing.PartColors;
+        public string Name { get; set; } = "Unnamed";
+
+        public Color[] PartColors { get; set; } = Drawing.PartColors;
 
         public static readonly ColorScheme Default = new ColorScheme
         {
+            Name = "Classic",
             BackgroundColor = Color.DarkGray,
             LayoutOutlineColor = Color.Gray,
             LayoutFillColor = Color.WhiteSmoke,

OpenNest/ColorSchemeSerializer.cs

@@ -0,0 +1,82 @@
+using System.Drawing;
+using System.Globalization;
+using System.Linq;
+using System.Text.Json;
+
+namespace OpenNest
+{
+    public static class ColorSchemeSerializer
+    {
+        private static readonly JsonSerializerOptions JsonOptions = new()
+        {
+            WriteIndented = true,
+            PropertyNamingPolicy = JsonNamingPolicy.CamelCase
+        };
+
+        public static string Serialize(ColorScheme scheme)
+        {
+            var dto = new ColorSchemeDto
+            {
+                Name = scheme.Name,
+                BackgroundColor = ToHex(scheme.BackgroundColor),
+                LayoutOutlineColor = ToHex(scheme.LayoutOutlineColor),
+                LayoutFillColor = ToHex(scheme.LayoutFillColor),
+                BoundingBoxColor = ToHex(scheme.BoundingBoxColor),
+                RapidColor = ToHex(scheme.RapidColor),
+                OriginColor = ToHex(scheme.OriginColor),
+                EdgeSpacingColor = ToHex(scheme.EdgeSpacingColor),
+                PreviewPartColor = ToHex(scheme.PreviewPartColor),
+                PartColors = scheme.PartColors.Select(ToHex).ToArray()
+            };
+            return JsonSerializer.Serialize(dto, JsonOptions);
+        }
+
+        public static ColorScheme Deserialize(string json)
+        {
+            var dto = JsonSerializer.Deserialize<ColorSchemeDto>(json, JsonOptions)
+                ?? throw new JsonException("ColorScheme JSON was null");
+
+            return new ColorScheme
+            {
+                Name = dto.Name ?? "Unnamed",
+                BackgroundColor = FromHex(dto.BackgroundColor),
+                LayoutOutlineColor = FromHex(dto.LayoutOutlineColor),
+                LayoutFillColor = FromHex(dto.LayoutFillColor),
+                BoundingBoxColor = FromHex(dto.BoundingBoxColor),
+                RapidColor = FromHex(dto.RapidColor),
+                OriginColor = FromHex(dto.OriginColor),
+                EdgeSpacingColor = FromHex(dto.EdgeSpacingColor),
+                PreviewPartColor = FromHex(dto.PreviewPartColor),
+                PartColors = (dto.PartColors ?? new string[0]).Select(FromHex).ToArray()
+            };
+        }
+
+        private static string ToHex(Color c) =>
+            "#" + c.R.ToString("X2") + c.G.ToString("X2") + c.B.ToString("X2");
+
+        private static Color FromHex(string hex)
+        {
+            if (string.IsNullOrWhiteSpace(hex))
+                return Color.Black;
+            var h = hex.TrimStart('#');
+            var r = byte.Parse(h.Substring(0, 2), NumberStyles.HexNumber, CultureInfo.InvariantCulture);
+            var g = byte.Parse(h.Substring(2, 2), NumberStyles.HexNumber, CultureInfo.InvariantCulture);
+            var b = byte.Parse(h.Substring(4, 2), NumberStyles.HexNumber, CultureInfo.InvariantCulture);
+            return Color.FromArgb(r, g, b);
+        }
+
+        private class ColorSchemeDto
+        {
+            public string Name { get; set; }
+            public string BackgroundColor { get; set; }
+            public string LayoutOutlineColor { get; set; }
+            public string LayoutFillColor { get; set; }
+            public string BoundingBoxColor { get; set; }
+            public string RapidColor { get; set; }
+            public string OriginColor { get; set; }
+            public string EdgeSpacingColor { get; set; }
+            public string PreviewPartColor { get; set; }
+            public string[] PartColors { get; set; }
+        }
+    }
+}