refactor: Relocate Document, BinFileSaver, and Toolbox to proper folders

- Move Document.cs from Forms to Models namespace
- Move BinFileSaver.cs and Toolbox.cs from Forms to Services namespace
- Better separation of concerns between UI and business logic

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

CutList/Services/BinFileSaver.cs

@@ -0,0 +1,131 @@
+using CutList.Core;
+using CutList.Core.Formatting;
+using System.Diagnostics;
+
+namespace CutList.Services
+{
+    public class BinFileSaver
+    {
+        private readonly IEnumerable<Bin> _bins;
+
+        private int PaddingWidthOfItemLength { get; set; }
+
+        public bool OpenFileAfterSave { get; set; }
+
+        public BinFileSaver(IEnumerable<Bin> bins)
+        {
+            _bins = bins ?? throw new ArgumentNullException(nameof(bins));
+        }
+
+        public void SaveBinsToFile(string file)
+        {
+            using (var writer = new StreamWriter(file))
+            {
+                writer.AutoFlush = true;
+
+                PaddingWidthOfItemLength = _bins
+                    .SelectMany(b => b.Items)
+                    .Select(i => FormatHelper.ConvertToMixedFraction(i.Length).Length)
+                    .DefaultIfEmpty(0)
+                    .Max();
+
+                WriteHeader(writer);
+
+                var id = 1;
+                foreach (var bin in _bins)
+                {
+                    WriteBinSummary(writer, bin, id++);
+                }
+
+                WriteFinalSummary(writer);
+            }
+
+            if (OpenFileAfterSave)
+            {
+                OpenFile(file);
+            }
+        }
+
+        private void OpenFile(string file)
+        {
+            try
+            {
+                Process.Start("notepad.exe", file);
+            }
+            catch
+            {
+                Process.Start(file);
+            }
+        }
+
+        private void WriteHeader(StreamWriter writer)
+        {
+            var totalBars = _bins.Count();
+            var totalItems = _bins.Sum(b => b.Items.Count);
+
+            writer.WriteLine("CUT LIST");
+            writer.WriteLine($"Date: {DateTime.Now:g}");
+            writer.WriteLine($"Total stock bars needed: {totalBars}");
+            writer.WriteLine($"Total pieces to cut: {totalItems}");
+            writer.WriteLine();
+        }
+
+        private void WriteBinSummary(StreamWriter writer, Bin bin, int id)
+        {
+            var stockLength = FormatHelper.ConvertToMixedFraction(bin.Length);
+            var dropLength = FormatHelper.ConvertToMixedFraction(bin.RemainingLength);
+
+            writer.WriteLine(new string('─', 50));
+            writer.WriteLine($"BAR #{id}  -  Start with {stockLength}\" stock");
+            writer.WriteLine();
+            writer.WriteLine("  Cut these pieces:");
+
+            WriteBinItems(writer, bin);
+
+            writer.WriteLine();
+            writer.WriteLine($"  Remaining drop: {dropLength}\"");
+            writer.WriteLine();
+        }
+
+        private void WriteBinItems(StreamWriter writer, Bin bin)
+        {
+            var groups = bin.Items
+                .GroupBy(i => new { i.Name, i.Length })
+                .OrderBy(g => g.Key.Name)
+                .ThenBy(g => g.Key.Length);
+
+            var lengthHeader = "LENGTH".PadLeft(PaddingWidthOfItemLength + 1);
+            writer.WriteLine($"    QTY   {lengthHeader}   LABEL");
+
+            foreach (var group in groups)
+            {
+                var first = group.First();
+                var count = group.Count();
+                var length = FormatHelper
+                    .ConvertToMixedFraction(first.Length)
+                    .PadLeft(PaddingWidthOfItemLength) + "\"";
+
+                writer.WriteLine($"    {count,3}   {length}   {first.Name}");
+            }
+        }
+
+        private void WriteFinalSummary(StreamWriter writer)
+        {
+            var totalBars = _bins.Count();
+            var totalItems = _bins.Sum(b => b.Items.Count);
+            var totalStock = _bins.Sum(b => b.Length);
+            var totalDrop = _bins.Sum(b => b.RemainingLength);
+
+            string fmt(double v) => FormatHelper.ConvertToMixedFraction(v);
+
+            writer.WriteLine(new string('═', 50));
+            writer.WriteLine("SUMMARY");
+            writer.WriteLine($"  Stock bars needed: {totalBars}");
+            writer.WriteLine($"  Total pieces to cut: {totalItems}");
+            writer.WriteLine($"  Total material used: {fmt(totalStock)}\"");
+            writer.WriteLine($"  Total drop/waste: {fmt(totalDrop)}\"");
+            writer.WriteLine(new string('═', 50));
+        }
+
+    }
+}

CutList/Services/Toolbox.cs

@@ -0,0 +1,54 @@
+using Newtonsoft.Json;
+
+namespace CutList.Services
+{
+    public class Toolbox
+    {
+        public Toolbox()
+        {
+            Load();
+        }
+
+        public List<Tool> Tools { get; set; }
+
+        public string ToolsFilePath { get; set; } = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "Data\\Tools.json");
+
+        private void LoadDefaultTools()
+        {
+            Tools = new List<Tool>
+            {
+                new Tool { Name = "Shear", Kerf = 0.0 },
+                new Tool { Name = "Saw", Kerf = 0.125 },
+                new Tool { Name = "Channel Muncher", Kerf = 0.5 },
+                new Tool { Name = "Custom", Kerf = 1, AllowUserToChange = true }
+            };
+        }
+
+        /// <summary>
+        /// Loads the tool list from the file at ToolsFilePath
+        /// </summary>
+        public void Load()
+        {
+            if (!File.Exists(ToolsFilePath))
+            {
+                LoadDefaultTools();
+                Save();
+            }
+            else
+            {
+                var json = File.ReadAllText(ToolsFilePath);
+                var list = JsonConvert.DeserializeObject<List<Tool>>(json);
+                Tools = list;
+            }
+        }
+
+        public void Save()
+        {
+            if (Tools == null)
+                return;
+
+            var json = JsonConvert.SerializeObject(Tools, Formatting.Indented);
+            File.WriteAllText(ToolsFilePath, json);
+        }
+    }
+}