docs: add design plans for API and auto-fill features

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

ExportDXF.sln

@@ -1,14 +1,12 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio Version 16
-VisualStudioVersion = 16.0.29123.88
+# Visual Studio Version 18
+VisualStudioVersion = 18.3.11512.155 d18.3
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ExportDXF", "ExportDXF\ExportDXF.csproj", "{05F21D73-FD31-4E77-8D9B-41C86D4D8305}"
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "EtchBendLines", "EtchBendLines\EtchBendLines\EtchBendLines.csproj", "{229C2FB9-6AD6-4A5D-B83A-D1146573D6F9}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "netDxf", "EtchBendLines\netDxf\netDxf\netDxf.csproj", "{785380E0-CEB9-4C34-82E5-60D0E33E848E}"
-EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "FabWorks.Core", "FabWorks.Core\FabWorks.Core.csproj", "{24547EE4-2EAA-4A6C-AD94-1117C038D8CD}"
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "FabWorks.Tests", "FabWorks.Tests\FabWorks.Tests.csproj", "{6DD89774-D86B-47E9-B982-2794BD95616A}"
@@ -49,18 +47,6 @@ Global
 		{229C2FB9-6AD6-4A5D-B83A-D1146573D6F9}.Release|x64.Build.0 = Release|Any CPU
 		{229C2FB9-6AD6-4A5D-B83A-D1146573D6F9}.Release|x86.ActiveCfg = Release|Any CPU
 		{229C2FB9-6AD6-4A5D-B83A-D1146573D6F9}.Release|x86.Build.0 = Release|Any CPU
-		{785380E0-CEB9-4C34-82E5-60D0E33E848E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{785380E0-CEB9-4C34-82E5-60D0E33E848E}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{785380E0-CEB9-4C34-82E5-60D0E33E848E}.Debug|x64.ActiveCfg = Debug|Any CPU
-		{785380E0-CEB9-4C34-82E5-60D0E33E848E}.Debug|x64.Build.0 = Debug|Any CPU
-		{785380E0-CEB9-4C34-82E5-60D0E33E848E}.Debug|x86.ActiveCfg = Debug|Any CPU
-		{785380E0-CEB9-4C34-82E5-60D0E33E848E}.Debug|x86.Build.0 = Debug|Any CPU
-		{785380E0-CEB9-4C34-82E5-60D0E33E848E}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{785380E0-CEB9-4C34-82E5-60D0E33E848E}.Release|Any CPU.Build.0 = Release|Any CPU
-		{785380E0-CEB9-4C34-82E5-60D0E33E848E}.Release|x64.ActiveCfg = Release|Any CPU
-		{785380E0-CEB9-4C34-82E5-60D0E33E848E}.Release|x64.Build.0 = Release|Any CPU
-		{785380E0-CEB9-4C34-82E5-60D0E33E848E}.Release|x86.ActiveCfg = Release|Any CPU
-		{785380E0-CEB9-4C34-82E5-60D0E33E848E}.Release|x86.Build.0 = Release|Any CPU
 		{24547EE4-2EAA-4A6C-AD94-1117C038D8CD}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{24547EE4-2EAA-4A6C-AD94-1117C038D8CD}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{24547EE4-2EAA-4A6C-AD94-1117C038D8CD}.Debug|x64.ActiveCfg = Debug|Any CPU

ExportDXF/DrawingInfo.cs

@@ -1,3 +1,4 @@
+using System.IO;
 using System.Text.RegularExpressions;
 
 namespace ExportDXF
@@ -13,6 +14,35 @@ namespace ExportDXF
 
         public string Source { get; set; }
 
+        /// <summary>
+        /// The descriptive text after the equipment/drawing number (e.g. "Prox switch bracket for drive").
+        /// </summary>
+        public string Description
+        {
+            get
+            {
+                if (string.IsNullOrEmpty(Source) || string.IsNullOrEmpty(EquipmentNo))
+                    return null;
+
+                // Strip equipment number (and optional drawing number) from the source to get the description
+                var prefix = string.IsNullOrEmpty(DrawingNo)
+                    ? EquipmentNo
+                    : EquipmentNo + " " + DrawingNo;
+
+                var desc = Source;
+                if (desc.StartsWith(prefix, System.StringComparison.OrdinalIgnoreCase))
+                    desc = desc.Substring(prefix.Length);
+
+                // Remove file extension (e.g. ".SLDPRT")
+                var ext = Path.GetExtension(desc);
+                if (!string.IsNullOrEmpty(ext))
+                    desc = desc.Substring(0, desc.Length - ext.Length);
+
+                desc = desc.Trim();
+                return string.IsNullOrEmpty(desc) ? null : desc;
+            }
+        }
+
         public override string ToString()
         {
             if (string.IsNullOrEmpty(DrawingNo))

ExportDXF/ExportDXF.csproj

@@ -14,6 +14,9 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="CoenM.ImageSharp.ImageHash" Version="1.1.5" />
+    <PackageReference Include="PDFtoImage" Version="4.1.1" />
+    <PackageReference Include="SixLabors.ImageSharp" Version="3.1.7" />
     <PackageReference Include="System.Configuration.ConfigurationManager" Version="8.0.0" />
   </ItemGroup>
 

ExportDXF/Forms/MainForm.Designer.cs

@@ -114,16 +114,16 @@ namespace ExportDXF.Forms
             logEventsDataGrid.GridColor = System.Drawing.Color.WhiteSmoke;
             logEventsDataGrid.Location = new System.Drawing.Point(6, 6);
             logEventsDataGrid.Name = "logEventsDataGrid";
-            logEventsDataGrid.Size = new System.Drawing.Size(890, 440);
+            logEventsDataGrid.Size = new System.Drawing.Size(890, 444);
             logEventsDataGrid.TabIndex = 0;
             // 
             // bomTab
             // 
             bomTab.Controls.Add(bomDataGrid);
-            bomTab.Location = new System.Drawing.Point(4, 28);
+            bomTab.Location = new System.Drawing.Point(4, 30);
             bomTab.Name = "bomTab";
             bomTab.Padding = new System.Windows.Forms.Padding(3);
-            bomTab.Size = new System.Drawing.Size(902, 409);
+            bomTab.Size = new System.Drawing.Size(902, 458);
             bomTab.TabIndex = 1;
             bomTab.Text = "Bill Of Materials";
             bomTab.UseVisualStyleBackColor = true;
@@ -135,16 +135,16 @@ namespace ExportDXF.Forms
             bomDataGrid.GridColor = System.Drawing.Color.WhiteSmoke;
             bomDataGrid.Location = new System.Drawing.Point(6, 6);
             bomDataGrid.Name = "bomDataGrid";
-            bomDataGrid.Size = new System.Drawing.Size(1281, 644);
+            bomDataGrid.Size = new System.Drawing.Size(890, 444);
             bomDataGrid.TabIndex = 1;
             // 
             // cutTemplatesTab
             // 
             cutTemplatesTab.Controls.Add(cutTemplatesDataGrid);
-            cutTemplatesTab.Location = new System.Drawing.Point(4, 28);
+            cutTemplatesTab.Location = new System.Drawing.Point(4, 30);
             cutTemplatesTab.Name = "cutTemplatesTab";
             cutTemplatesTab.Padding = new System.Windows.Forms.Padding(3);
-            cutTemplatesTab.Size = new System.Drawing.Size(902, 409);
+            cutTemplatesTab.Size = new System.Drawing.Size(902, 458);
             cutTemplatesTab.TabIndex = 2;
             cutTemplatesTab.Text = "Cut Templates";
             cutTemplatesTab.UseVisualStyleBackColor = true;
@@ -156,7 +156,7 @@ namespace ExportDXF.Forms
             cutTemplatesDataGrid.GridColor = System.Drawing.Color.WhiteSmoke;
             cutTemplatesDataGrid.Location = new System.Drawing.Point(6, 6);
             cutTemplatesDataGrid.Name = "cutTemplatesDataGrid";
-            cutTemplatesDataGrid.Size = new System.Drawing.Size(1281, 644);
+            cutTemplatesDataGrid.Size = new System.Drawing.Size(890, 447);
             cutTemplatesDataGrid.TabIndex = 2;
             // 
             // equipmentBox

ExportDXF/Forms/MainForm.cs

@@ -487,6 +487,9 @@ namespace ExportDXF.Forms
                     equipmentBox.Text = drawingInfo.EquipmentNo;
                 }
 
+                if (string.IsNullOrEmpty(titleBox.Text) && !string.IsNullOrEmpty(drawingInfo.Description))
+                    titleBox.Text = drawingInfo.Description;
+
                 // Load drawings for the selected equipment, then set drawing number
                 await UpdateDrawingDropdownAsync();
 

ExportDXF/Services/DxfExportService.cs

@@ -207,7 +207,6 @@ namespace ExportDXF.Services
         private async Task ExportDrawingAsync(ExportContext context, string drawingNumber, string tempDir)
         {
             LogProgress(context, "Active document is a Drawing");
-            LogProgress(context, "Finding BOM tables...");
 
             var drawing = context.ActiveDocument.NativeDocument as DrawingDoc;
             if (drawing == null)
@@ -216,16 +215,6 @@ namespace ExportDXF.Services
                 return;
             }
 
-            var items = _bomExtractor.ExtractFromDrawing(drawing, context.ProgressCallback);
-
-            if (items == null || items.Count == 0)
-            {
-                LogProgress(context, "Error: Bill of materials not found.", LogLevel.Error);
-                return;
-            }
-
-            LogProgress(context, $"Found {items.Count} component(s)");
-
             // Export drawing to PDF in temp dir
             _drawingExporter.ExportToPdf(drawing, tempDir, context);
 
@@ -239,7 +228,7 @@ namespace ExportDXF.Services
                 if (pdfs.Length > 0)
                 {
                     var pdfTempPath = pdfs[0];
-                    var pdfHash = ContentHasher.ComputeFileHash(pdfTempPath);
+                    var pdfHash = ContentHasher.ComputePdfContentHash(pdfTempPath);
 
                     var uploadResult = await _apiClient.UploadPdfAsync(
                         pdfTempPath,
@@ -264,8 +253,74 @@ namespace ExportDXF.Services
                 LogProgress(context, $"PDF upload error: {ex.Message}", LogLevel.Error);
             }
 
-            // Export parts to DXF and save BOM items
-            await ExportItemsAsync(items, tempDir, context, exportRecord?.Id);
+            // Extract BOM items from drawing tables
+            LogProgress(context, "Finding BOM tables...");
+            var items = _bomExtractor.ExtractFromDrawing(drawing, context.ProgressCallback);
+
+            if (items != null && items.Count > 0)
+            {
+                LogProgress(context, $"Found {items.Count} component(s)");
+                await ExportItemsAsync(items, tempDir, context, exportRecord?.Id);
+            }
+            else
+            {
+                // No BOM table — fall back to exporting the part referenced by the drawing views
+                LogProgress(context, "No BOM table found. Checking drawing views for referenced part...");
+
+                var (part, configuration) = GetReferencedPartFromViews(drawing);
+                if (part == null)
+                {
+                    LogProgress(context, "No referenced part found in drawing views.", LogLevel.Warning);
+                    return;
+                }
+
+                LogProgress(context, $"Found referenced part, exporting as single part...");
+
+                var item = _partExporter.ExportSinglePart(part, tempDir, context);
+                if (item != null)
+                {
+                    if (!string.IsNullOrEmpty(configuration))
+                        item.Configuration = configuration;
+
+                    var existingItemNo = await FindExistingItemNoAsync(exportRecord?.Id, item.PartName, item.Configuration);
+                    item.ItemNo = existingItemNo ?? await GetNextItemNumberAsync(drawingNumber);
+
+                    var bomItem = new BomItem
+                    {
+                        ExportRecordId = exportRecord?.Id ?? 0,
+                        ItemNo = item.ItemNo,
+                        PartNo = item.FileName ?? item.PartName ?? "",
+                        SortOrder = 0,
+                        Qty = item.Quantity,
+                        TotalQty = item.Quantity,
+                        Description = item.Description ?? "",
+                        PartName = item.PartName ?? "",
+                        ConfigurationName = item.Configuration ?? "",
+                        Material = item.Material ?? ""
+                    };
+
+                    if (!string.IsNullOrEmpty(item.LocalTempPath))
+                    {
+                        var uploadResult = await UploadDxfAsync(item, context);
+                        if (uploadResult != null)
+                        {
+                            bomItem.CutTemplate = new CutTemplate
+                            {
+                                DxfFilePath = uploadResult.StoredFilePath,
+                                ContentHash = item.ContentHash,
+                                Thickness = item.Thickness > 0 ? item.Thickness : null,
+                                KFactor = item.KFactor > 0 ? item.KFactor : null,
+                                DefaultBendRadius = item.BendRadius > 0 ? item.BendRadius : null
+                            };
+                        }
+                    }
+
+                    context.BomItemCallback?.Invoke(bomItem);
+
+                    if (exportRecord != null)
+                        await SaveBomItemAsync(exportRecord.Id, bomItem, context);
+                }
+            }
         }
 
         #endregion
@@ -600,6 +655,24 @@ namespace ExportDXF.Services
                 throw new ArgumentException("ProgressCallback cannot be null.", nameof(context));
         }
 
+        private (PartDoc part, string configuration) GetReferencedPartFromViews(DrawingDoc drawing)
+        {
+            var view = (IView)drawing.GetFirstView();
+            // First view is the sheet itself — skip it
+            view = (IView)view.GetNextView();
+
+            while (view != null)
+            {
+                var doc = view.ReferencedDocument;
+                if (doc is PartDoc part)
+                    return (part, view.ReferencedConfiguration);
+
+                view = (IView)view.GetNextView();
+            }
+
+            return (null, null);
+        }
+
         private void LogProgress(ExportContext context, string message, LogLevel level = LogLevel.Info, string file = null)
         {
             context.ProgressCallback?.Invoke(message, level, file);

ExportDXF/Services/PartExporter.cs

@@ -234,7 +234,7 @@ namespace ExportDXF.Services
                 var drawingModel = templateDrawing as ModelDoc2;
                 drawingModel.SaveAs(savePath);
 
-                AddEtchLines(savePath);
+                AddEtchLines(savePath, context);
 
                 context.ProgressCallback?.Invoke($"Saved to \"{savePath}\"", LogLevel.Info, partTitle);
 
@@ -301,7 +301,7 @@ namespace ExportDXF.Services
             drawing.DeleteSelection(false);
         }
 
-        private void AddEtchLines(string dxfPath)
+        private void AddEtchLines(string dxfPath, ExportContext context)
         {
             try
             {
@@ -309,9 +309,9 @@ namespace ExportDXF.Services
                 etcher.AddEtchLines(dxfPath);
                 FixDegreeSymbol(dxfPath);
             }
-            catch (Exception)
+            catch (Exception ex)
             {
-                // Silently fail if etch lines can't be added
+                context.ProgressCallback?.Invoke($"Etch lines failed: {ex.Message}", LogLevel.Warning, Path.GetFileName(dxfPath));
             }
         }
 

ExportDXF/Utilities/ContentHasher.cs

@@ -1,26 +1,67 @@
 using System;
+using System.Collections.Generic;
+using System.Globalization;
 using System.IO;
+using System.Linq;
 using System.Security.Cryptography;
 using System.Text;
+using ACadSharp.Entities;
+using ACadSharp.IO;
+using CoenM.ImageHash;
+using CoenM.ImageHash.HashAlgorithms;
+using PDFtoImage;
+using SixLabors.ImageSharp;
+using SixLabors.ImageSharp.PixelFormats;
 
 namespace ExportDXF.Utilities
 {
     public static class ContentHasher
     {
         /// <summary>
-        /// Computes a SHA256 hash of DXF file content, skipping the HEADER section
-        /// which contains timestamps that change on every save.
+        /// Computes a SHA256 hash of DXF geometry, ignoring entity ordering,
+        /// handle assignments, style names, and floating-point epsilon differences
+        /// that SolidWorks changes between re-exports of identical geometry.
+        /// Falls back to a raw file hash if ACadSharp parsing fails.
         /// </summary>
         public static string ComputeDxfContentHash(string filePath)
         {
-            var text = File.ReadAllText(filePath);
-            var contentStart = FindEndOfHeader(text);
-            var content = contentStart >= 0 ? text.Substring(contentStart) : text;
-
-            using (var sha = SHA256.Create())
+            try
             {
-                var bytes = sha.ComputeHash(Encoding.UTF8.GetBytes(content));
-                return BitConverter.ToString(bytes).Replace("-", "").ToLowerInvariant();
+                return ComputeGeometricHash(filePath);
+            }
+            catch
+            {
+                return ComputeFileHash(filePath);
+            }
+        }
+
+        /// <summary>
+        /// Computes a perceptual hash of a PDF by rendering page 1 to an image,
+        /// so only visual changes affect the hash (metadata/timestamp changes are ignored).
+        /// Falls back to a raw file hash if rendering fails.
+        /// </summary>
+        public static string ComputePdfContentHash(string filePath)
+        {
+            try
+            {
+                using (var pdfStream = File.OpenRead(filePath))
+                using (var pngStream = new MemoryStream())
+                {
+                    Conversion.SavePng(pngStream, pdfStream, page: 0,
+                        options: new RenderOptions(Dpi: 72));
+                    pngStream.Position = 0;
+
+                    using (var image = Image.Load<Rgba32>(pngStream))
+                    {
+                        var algorithm = new DifferenceHash();
+                        var hash = algorithm.Hash(image);
+                        return hash.ToString("x16");
+                    }
+                }
+            }
+            catch
+            {
+                return ComputeFileHash(filePath);
             }
         }
 
@@ -37,82 +78,95 @@ namespace ExportDXF.Utilities
             }
         }
 
-        /// <summary>
-        /// Finds the position immediately after the HEADER section's ENDSEC marker.
-        /// DXF HEADER format:
-        ///   0\nSECTION\n2\nHEADER\n...variables...\n0\nENDSEC\n
-        /// Returns -1 if no HEADER section is found.
-        /// </summary>
-        private static int FindEndOfHeader(string text)
+        private static string ComputeGeometricHash(string filePath)
         {
-            // Find the HEADER section start
-            var headerIndex = FindGroupCode(text, 0, "2", "HEADER");
-            if (headerIndex < 0)
-                return -1;
-
-            // Advance past the HEADER value line so pair scanning stays aligned
-            var headerLineEnd = text.IndexOf('\n', headerIndex);
-            if (headerLineEnd < 0)
-                return -1;
-
-            // Find the ENDSEC that closes the HEADER section
-            var pos = headerLineEnd + 1;
-            while (pos < text.Length)
+            using (var reader = new DxfReader(filePath))
             {
-                var endsecIndex = FindGroupCode(text, pos, "0", "ENDSEC");
-                if (endsecIndex < 0)
-                    return -1;
+                var doc = reader.Read();
+                var signatures = new List<string>();
 
-                // Move past the ENDSEC line
-                var lineEnd = text.IndexOf('\n', endsecIndex);
-                return lineEnd >= 0 ? lineEnd + 1 : text.Length;
+                foreach (var entity in doc.Entities)
+                {
+                    signatures.Add(GetEntitySignature(entity));
+                }
+
+                signatures.Sort(StringComparer.Ordinal);
+                var combined = string.Join("\n", signatures);
+
+                using (var sha = SHA256.Create())
+                {
+                    var bytes = sha.ComputeHash(Encoding.UTF8.GetBytes(combined));
+                    return BitConverter.ToString(bytes).Replace("-", "").ToLowerInvariant();
+                }
             }
-
-            return -1;
         }
 
-        /// <summary>
-        /// Finds a DXF group code pair (code line followed by value line) starting from the given position.
-        /// Returns the position of the value line, or -1 if not found.
-        /// </summary>
-        private static int FindGroupCode(string text, int startIndex, string groupCode, string value)
+        private static string GetEntitySignature(Entity entity)
         {
-            var pos = startIndex;
-            while (pos < text.Length)
+            var layer = entity.Layer?.Name ?? "";
+
+            switch (entity)
             {
-                // Skip whitespace/newlines to find the group code
-                while (pos < text.Length && (text[pos] == '\r' || text[pos] == '\n' || text[pos] == ' '))
-                    pos++;
+                case Line line:
+                    return GetLineSignature(line, layer);
+                case Arc arc:
+                    return GetArcSignature(arc, layer);
+                case Circle circle:
+                    return GetCircleSignature(circle, layer);
+                case MText mtext:
+                    return GetMTextSignature(mtext, layer);
+                default:
+                    return $"{entity.GetType().Name}|{layer}";
+            }
+        }
 
-                if (pos >= text.Length)
-                    break;
+        private static string GetLineSignature(Line line, string layer)
+        {
+            var p1 = FormatPoint(line.StartPoint.X, line.StartPoint.Y);
+            var p2 = FormatPoint(line.EndPoint.X, line.EndPoint.Y);
 
-                // Read the group code line
-                var codeLineEnd = text.IndexOf('\n', pos);
-                if (codeLineEnd < 0)
-                    break;
-
-                var codeLine = text.Substring(pos, codeLineEnd - pos).Trim();
-
-                // Move to the value line
-                var valueStart = codeLineEnd + 1;
-                if (valueStart >= text.Length)
-                    break;
-
-                var valueLineEnd = text.IndexOf('\n', valueStart);
-                if (valueLineEnd < 0)
-                    valueLineEnd = text.Length;
-
-                var valueLine = text.Substring(valueStart, valueLineEnd - valueStart).Trim();
-
-                if (codeLine == groupCode && string.Equals(valueLine, value, StringComparison.OrdinalIgnoreCase))
-                    return valueStart;
-
-                // Move to the next pair
-                pos = valueLineEnd + 1;
+            // Normalize endpoint order so direction doesn't affect the hash
+            if (string.Compare(p1, p2, StringComparison.Ordinal) > 0)
+            {
+                var tmp = p1;
+                p1 = p2;
+                p2 = tmp;
             }
 
-            return -1;
+            return $"LINE|{layer}|{p1}|{p2}";
+        }
+
+        private static string GetArcSignature(Arc arc, string layer)
+        {
+            var center = FormatPoint(arc.Center.X, arc.Center.Y);
+            var r = R(arc.Radius);
+            var sa = R(arc.StartAngle);
+            var ea = R(arc.EndAngle);
+            return $"ARC|{layer}|{center}|{r}|{sa}|{ea}";
+        }
+
+        private static string GetCircleSignature(Circle circle, string layer)
+        {
+            var center = FormatPoint(circle.Center.X, circle.Center.Y);
+            var r = R(circle.Radius);
+            return $"CIRCLE|{layer}|{center}|{r}";
+        }
+
+        private static string GetMTextSignature(MText mtext, string layer)
+        {
+            var point = FormatPoint(mtext.InsertPoint.X, mtext.InsertPoint.Y);
+            var text = mtext.Value ?? "";
+            return $"MTEXT|{layer}|{point}|{text}";
+        }
+
+        private static string R(double value)
+        {
+            return Math.Round(value, 4).ToString(CultureInfo.InvariantCulture);
+        }
+
+        private static string FormatPoint(double x, double y)
+        {
+            return $"{R(x)},{R(y)}";
         }
     }
 }

FabWorks.Api/Controllers/ExportsController.cs

@@ -212,11 +212,50 @@ namespace FabWorks.Api.Controllers
             if (record == null) return NotFound();
 
             record.PdfContentHash = request.PdfContentHash;
+
+            if (!string.IsNullOrEmpty(record.DrawingNumber) && !string.IsNullOrEmpty(request.PdfContentHash))
+            {
+                var drawing = await ResolveDrawingAsync(record.DrawingNumber, record.Title, request.PdfContentHash);
+                record.DrawingId = drawing.Id;
+            }
+
             await _db.SaveChangesAsync();
 
             return NoContent();
         }
 
+        private async Task<Drawing> ResolveDrawingAsync(string drawingNumber, string title, string pdfContentHash)
+        {
+            var drawing = await _db.Drawings
+                .FirstOrDefaultAsync(d => d.DrawingNumber == drawingNumber);
+
+            if (drawing == null)
+            {
+                drawing = new Drawing
+                {
+                    DrawingNumber = drawingNumber,
+                    Title = title,
+                    PdfContentHash = pdfContentHash,
+                    Revision = 1
+                };
+                _db.Drawings.Add(drawing);
+            }
+            else if (drawing.PdfContentHash != pdfContentHash)
+            {
+                drawing.PdfContentHash = pdfContentHash;
+                drawing.Revision++;
+                if (!string.IsNullOrEmpty(title))
+                    drawing.Title = title;
+            }
+            // If hash matches, keep same revision (just update title if needed)
+            else if (!string.IsNullOrEmpty(title))
+            {
+                drawing.Title = title;
+            }
+
+            return drawing;
+        }
+
         [HttpGet("previous-cut-template")]
         public async Task<ActionResult<CutTemplateDto>> GetPreviousCutTemplate(
             [FromQuery] string drawingNumber,

FabWorks.Api/Controllers/FileBrowserController.cs

@@ -38,6 +38,7 @@ namespace FabWorks.Api.Controllers
                         c.DxfFilePath,
                         c.ContentHash,
                         c.Thickness,
+                        c.Revision,
                         DrawingNumber = c.BomItem.ExportRecord.DrawingNumber,
                         CreatedAt = c.BomItem.ExportRecord.ExportedAt
                     });
@@ -70,6 +71,7 @@ namespace FabWorks.Api.Controllers
                         FileType = "dxf",
                         DrawingNumber = c.DrawingNumber,
                         Thickness = c.Thickness,
+                        Revision = c.Revision,
                         CreatedAt = c.CreatedAt
                     });
                 }
@@ -85,7 +87,8 @@ namespace FabWorks.Api.Controllers
                         r.Id,
                         r.DrawingNumber,
                         r.PdfContentHash,
-                        r.ExportedAt
+                        r.ExportedAt,
+                        DrawingRevision = r.Drawing != null ? (int?)r.Drawing.Revision : null
                     });
 
                 if (!string.IsNullOrWhiteSpace(search))
@@ -113,6 +116,7 @@ namespace FabWorks.Api.Controllers
                         ContentHash = r.PdfContentHash,
                         FileType = "pdf",
                         DrawingNumber = r.DrawingNumber,
+                        Revision = r.DrawingRevision,
                         CreatedAt = r.ExportedAt
                     });
                 }
@@ -179,6 +183,7 @@ namespace FabWorks.Api.Controllers
         public string FileType { get; set; }
         public string DrawingNumber { get; set; }
         public double? Thickness { get; set; }
+        public int? Revision { get; set; }
         public DateTime CreatedAt { get; set; }
     }
 }

FabWorks.Api/wwwroot/js/pages.js

@@ -32,7 +32,7 @@ const pages = {
             setPage('Exports', `${data.items.length} exports`);
 
             const rows = data.items.map((e, i) => `
-                <tr class="clickable" onclick="router.go('export-detail', {id: ${e.id}})" style="animation: fadeSlideIn 0.2s ease ${0.02 * Math.min(i, 25)}s forwards; opacity: 0">
+                <tr class="clickable" onclick="router.go('drawing-detail', {id: '${encodeURIComponent(e.drawingNumber)}', eid: '${e.id}'})" style="animation: fadeSlideIn 0.2s ease ${0.02 * Math.min(i, 25)}s forwards; opacity: 0">
                     <td style="font-family:var(--font-mono);color:var(--text-dim);font-size:13px">${e.id}</td>
                     <td><strong>${esc(e.drawingNumber) || '<span style="color:var(--text-dim)">\u2014</span>'}</strong></td>
                     <td style="color:var(--text-secondary);font-size:13px">${esc(e.title) || ''}</td>
@@ -62,85 +62,6 @@ const pages = {
         }
     },
 
-    async exportDetail(id) {
-        const actions = document.getElementById('topbar-actions');
-        const content = document.getElementById('page-content');
-        setPage('Loading...');
-        actions.innerHTML = '';
-        content.innerHTML = `<div class="loading">Loading export</div>`;
-
-        try {
-            const exp = await api.get(`/api/exports/${id}`);
-            setPage(exp.drawingNumber || `Export #${exp.id}`, 'export detail');
-
-            const dxfCount = (exp.bomItems || []).filter(b => b.cutTemplate?.contentHash).length;
-
-            const bomRows = (exp.bomItems || []).map((b, i) => {
-                const hasDetails = b.cutTemplate || b.formProgram;
-                const toggleId = `bom-${b.id}`;
-                return `
-                    <tr class="${hasDetails ? 'clickable' : ''}" ${hasDetails ? `onclick="toggleBomRow('${toggleId}')"` : ''} style="animation: fadeSlideIn 0.25s ease ${0.03 * i}s forwards; opacity: 0">
-                        <td style="width:32px">${hasDetails ? `<span class="chevron-toggle" id="${toggleId}-icon">${icons.chevron}</span>` : ''}</td>
-                        <td style="font-family:var(--font-mono);font-weight:600;color:var(--cyan)">${esc(b.itemNo)}</td>
-                        <td><strong>${esc(b.partName)}</strong></td>
-                        <td style="color:var(--text-secondary)">${esc(b.description)}</td>
-                        <td><span style="font-family:var(--font-mono);font-size:13px">${esc(b.material)}</span></td>
-                        <td style="font-family:var(--font-mono);text-align:center">${b.qty ?? ''}</td>
-                        <td style="font-family:var(--font-mono);text-align:center">${b.totalQty ?? ''}</td>
-                        <td>
-                            ${b.cutTemplate ? `<span class="badge badge-cyan">${icons.laser} DXF</span>` : ''}
-                            ${b.formProgram ? `<span class="badge badge-amber">${icons.bend} Form</span>` : ''}
-                        </td>
-                    </tr>
-                    ${hasDetails ? `<tr class="bom-expand-row" id="${toggleId}" style="display:none"><td colspan="8">${renderBomDetails(b)}</td></tr>` : ''}`;
-            }).join('');
-
-            content.innerHTML = `
-                <a class="back-link" onclick="router.go('exports')">${icons.back} Back to exports</a>
-
-                <div class="card animate-in" style="margin-bottom:20px">
-                    <div class="card-header">Export Information</div>
-                    <div class="card-body">
-                        <div class="detail-grid">
-                            <div class="detail-field"><label>Drawing Number</label><div class="value">${esc(exp.drawingNumber) || '\u2014'}</div></div>
-                            ${exp.title ? `<div class="detail-field"><label>Title</label><div class="value">${esc(exp.title)}</div></div>` : ''}
-                            <div class="detail-field"><label>Exported By</label><div class="value">${esc(exp.exportedBy)}</div></div>
-                            <div class="detail-field"><label>Date</label><div class="value mono">${fmtDate(exp.exportedAt)}</div></div>
-                            <div class="detail-field"><label>Source File</label><div class="value mono">${esc(exp.sourceFilePath)}</div></div>
-                        </div>
-                    </div>
-                </div>
-
-                <div class="card animate-in">
-                    <div class="card-header">
-                        BOM Items
-                        <span class="badge badge-count">${exp.bomItems?.length || 0} items</span>
-                        <span style="margin-left:auto;display:flex;gap:6px">
-                            ${exp.pdfContentHash ? `<a class="btn btn-amber btn-sm" href="/api/filebrowser/download?hash=${encodeURIComponent(exp.pdfContentHash)}&ext=pdf&name=${encodeURIComponent((exp.drawingNumber || 'drawing') + '.pdf')}">${icons.download} PDF</a>` : ''}
-                            ${dxfCount > 0 ? `<a class="btn btn-cyan btn-sm" href="/api/exports/${exp.id}/download-dxfs">${icons.download} All DXFs</a>` : ''}
-                            <button class="btn btn-red btn-sm" onclick="deleteExport(${exp.id})">${icons.trash} Delete</button>
-                        </span>
-                    </div>
-                    ${exp.bomItems?.length ? `
-                    <table>
-                        <thead><tr>
-                            <th style="width:32px"></th>
-                            <th style="width:60px">Item</th>
-                            <th>Part Name</th>
-                            <th>Description</th>
-                            <th>Material</th>
-                            <th style="width:50px;text-align:center">Qty</th>
-                            <th style="width:55px;text-align:center">Total</th>
-                            <th style="width:120px">Data</th>
-                        </tr></thead>
-                        <tbody>${bomRows}</tbody>
-                    </table>` : '<div class="empty">No BOM items for this export.</div>'}
-                </div>`;
-        } catch (err) {
-            content.innerHTML = `<div class="empty">Error: ${esc(err.message)}</div>`;
-        }
-    },
-
     async drawings(params) {
         const actions = document.getElementById('topbar-actions');
         const content = document.getElementById('page-content');
@@ -255,8 +176,9 @@ const pages = {
         }
     },
 
-    async drawingDetail(drawingEncoded) {
+    async drawingDetail(drawingEncoded, params) {
         const drawingNumber = decodeURIComponent(drawingEncoded);
+        const exportId = params?.eid ? parseInt(params.eid) : null;
         const actions = document.getElementById('topbar-actions');
         const content = document.getElementById('page-content');
         setPage(drawingNumber, 'drawing');
@@ -273,12 +195,23 @@ const pages = {
                 return;
             }
 
-            const allBom = [];
-            exports.forEach(exp => {
-                (exp.bomItems || []).forEach(b => {
-                    allBom.push({ ...b, exportId: exp.id, exportedAt: exp.exportedAt });
+            let allBom;
+            const singleExport = exportId ? exports.find(e => e.id === exportId) : null;
+            if (singleExport) {
+                // Viewing a specific export - show only its BOM items
+                allBom = (singleExport.bomItems || []).map(b => ({ ...b, exportId: singleExport.id, exportedAt: singleExport.exportedAt }));
+            } else {
+                // Viewing drawing overview - deduplicate by itemNo, keeping latest revision (exports are newest-first)
+                const bomByItem = new Map();
+                exports.forEach(exp => {
+                    (exp.bomItems || []).forEach(b => {
+                        if (!bomByItem.has(b.itemNo)) {
+                            bomByItem.set(b.itemNo, { ...b, exportId: exp.id, exportedAt: exp.exportedAt });
+                        }
+                    });
                 });
-            });
+                allBom = [...bomByItem.values()];
+            }
 
             const bomRows = allBom.map((b, i) => {
                 const hasDetails = b.cutTemplate || b.formProgram;
@@ -288,6 +221,7 @@ const pages = {
                         <td style="width:32px">${hasDetails ? `<span class="chevron-toggle" id="${toggleId}-icon">${icons.chevron}</span>` : ''}</td>
                         <td style="font-family:var(--font-mono);font-weight:600;color:var(--cyan)">${esc(b.itemNo)}</td>
                         <td><strong>${esc(b.partName)}</strong></td>
+                        <td style="font-family:var(--font-mono);text-align:center;font-size:13px">${b.cutTemplate?.revision ?? ''}</td>
                         <td style="color:var(--text-secondary)">${esc(b.description)}</td>
                         <td><span style="font-family:var(--font-mono);font-size:13px">${esc(b.material)}</span></td>
                         <td style="font-family:var(--font-mono);text-align:center">${b.qty ?? ''}</td>
@@ -297,22 +231,43 @@ const pages = {
                             ${b.formProgram ? `<span class="badge badge-amber">${icons.bend} Form</span>` : ''}
                         </td>
                     </tr>
-                    ${hasDetails ? `<tr class="bom-expand-row" id="${toggleId}" style="display:none"><td colspan="8">${renderBomDetails(b)}</td></tr>` : ''}`;
+                    ${hasDetails ? `<tr class="bom-expand-row" id="${toggleId}" style="display:none"><td colspan="9">${renderBomDetails(b)}</td></tr>` : ''}`;
             }).join('');
 
-            content.innerHTML = `
-                <a class="back-link" onclick="router.go('drawings')">${icons.back} Back to drawings</a>
+            const backLink = singleExport
+                ? `<a class="back-link" onclick="router.go('exports')">${icons.back} Back to exports</a>`
+                : `<a class="back-link" onclick="router.go('drawings')">${icons.back} Back to drawings</a>`;
 
-                <div class="stats-grid">
+            const statsHtml = singleExport
+                ? `<div class="stats-grid">
+                    <div class="stat-card animate-in"><div class="stat-label">Exported By</div><div class="stat-value stat-sm">${esc(singleExport.exportedBy)}</div></div>
+                    <div class="stat-card animate-in"><div class="stat-label">BOM Items</div><div class="stat-value">${allBom.length}</div></div>
+                    <div class="stat-card animate-in"><div class="stat-label">Exported</div><div class="stat-value stat-sm">${fmtDate(singleExport.exportedAt)}</div></div>
+                </div>`
+                : `<div class="stats-grid">
                     <div class="stat-card animate-in"><div class="stat-label">Exports</div><div class="stat-value">${exports.length}</div></div>
                     <div class="stat-card animate-in"><div class="stat-label">BOM Items</div><div class="stat-value">${allBom.length}</div></div>
                     <div class="stat-card animate-in"><div class="stat-label">Latest Export</div><div class="stat-value stat-sm">${fmtDate(exports[0].exportedAt)}</div></div>
-                </div>
+                </div>`;
+
+            const bomHeader = singleExport ? 'BOM Items' : 'All BOM Items';
+            const activeExport = singleExport || exports[0];
+            const dxfCount = allBom.filter(b => b.cutTemplate?.contentHash).length;
+            const pdfHash = activeExport.pdfContentHash;
+            const pdfName = encodeURIComponent((drawingNumber || 'drawing') + '.pdf');
+
+            content.innerHTML = `
+                ${backLink}
+                ${statsHtml}
 
                 <div class="card animate-in">
                     <div class="card-header">
-                        All BOM Items
+                        ${bomHeader}
                         <span class="badge badge-count">${allBom.length} items</span>
+                        <span style="margin-left:auto;display:flex;gap:6px">
+                            ${pdfHash ? `<a class="btn btn-amber btn-sm" href="/api/filebrowser/download?hash=${encodeURIComponent(pdfHash)}&ext=pdf&name=${pdfName}">${icons.download} PDF</a>` : ''}
+                            ${dxfCount > 0 ? `<a class="btn btn-cyan btn-sm" href="/api/exports/${activeExport.id}/download-dxfs">${icons.download} All DXFs</a>` : ''}
+                        </span>
                     </div>
                     ${allBom.length ? `
                     <table>
@@ -320,6 +275,7 @@ const pages = {
                             <th style="width:32px"></th>
                             <th style="width:60px">Item</th>
                             <th>Part Name</th>
+                            <th style="width:45px;text-align:center">Rev</th>
                             <th>Description</th>
                             <th>Material</th>
                             <th style="width:50px;text-align:center">Qty</th>
@@ -397,6 +353,7 @@ const pages = {
                         <td><div class="file-name-cell">${ext === 'pdf' ? icons.filePdf : icons.fileDxf}<a href="/api/filebrowser/download?hash=${encodeURIComponent(f.contentHash)}&ext=${ext}&name=${encodeURIComponent(f.fileName)}">${esc(f.fileName)}</a></div></td>
                         <td><span class="badge ${ext === 'dxf' ? 'badge-cyan' : 'badge-amber'}">${ext.toUpperCase()}</span></td>
                         <td style="color:var(--text-secondary)">${esc(f.drawingNumber)}</td>
+                        <td style="font-family:var(--font-mono);font-size:13px;text-align:center;color:var(--text-secondary)">${f.revision != null ? f.revision : '\u2014'}</td>
                         <td style="font-family:var(--font-mono);font-size:13px;color:var(--text-secondary)">${f.thickness != null ? f.thickness.toFixed(4) + '"' : '\u2014'}</td>
                         <td style="font-family:var(--font-mono);font-size:13px;color:var(--text-secondary)">${fmtDate(f.createdAt)}</td>
                         <td style="font-family:var(--font-mono);font-size:12px;color:var(--text-dim)">${esc(hashShort)}</td>
@@ -413,6 +370,7 @@ const pages = {
                             <th>Name</th>
                             <th style="width:60px">Type</th>
                             <th>Drawing</th>
+                            <th style="width:45px;text-align:center">Rev</th>
                             <th style="width:90px">Thickness</th>
                             <th style="width:170px">Date</th>
                             <th style="width:100px">Hash</th>

FabWorks.Api/wwwroot/js/router.js

@@ -1,6 +1,9 @@
 const router = {
     go(page, params = {}) {
-        const hash = page + (params.id ? '/' + params.id : '') + (params.q ? '?q=' + encodeURIComponent(params.q) : '');
+        const qParts = [];
+        if (params.q) qParts.push('q=' + encodeURIComponent(params.q));
+        if (params.eid) qParts.push('eid=' + encodeURIComponent(params.eid));
+        const hash = page + (params.id ? '/' + params.id : '') + (qParts.length ? '?' + qParts.join('&') : '');
         location.hash = hash;
     },
     parse() {
@@ -20,12 +23,10 @@ const router = {
         document.querySelectorAll('.nav-item').forEach(el => {
             el.classList.toggle('active',
                 el.dataset.page === page ||
-                (page === 'export-detail' && el.dataset.page === 'exports') ||
                 (page === 'drawing-detail' && el.dataset.page === 'drawings'));
         });
         switch(page) {
             case 'exports': pages.exports(params); break;
-            case 'export-detail': pages.exportDetail(id); break;
             case 'drawings': pages.drawings(params); break;
             case 'drawing-detail': pages.drawingDetail(id, params); break;
             case 'files': pages.files(params); break;

FabWorks.Core/Data/FabWorksDbContext.cs

@@ -9,6 +9,7 @@ namespace FabWorks.Core.Data
         public DbSet<BomItem> BomItems { get; set; }
         public DbSet<CutTemplate> CutTemplates { get; set; }
         public DbSet<FormProgram> FormPrograms { get; set; }
+        public DbSet<Drawing> Drawings { get; set; }
 
         public FabWorksDbContext(DbContextOptions<FabWorksDbContext> options) : base(options) { }
 
@@ -32,6 +33,11 @@ namespace FabWorks.Core.Data
                       .WithOne(b => b.ExportRecord)
                       .HasForeignKey(b => b.ExportRecordId)
                       .OnDelete(DeleteBehavior.Cascade);
+
+                entity.HasOne(e => e.Drawing)
+                      .WithMany(d => d.ExportRecords)
+                      .HasForeignKey(e => e.DrawingId)
+                      .OnDelete(DeleteBehavior.SetNull);
             });
 
             modelBuilder.Entity<BomItem>(entity =>
@@ -74,6 +80,15 @@ namespace FabWorks.Core.Data
                 entity.Property(e => e.LowerToolNames).HasMaxLength(500);
                 entity.Property(e => e.SetupNotes).HasMaxLength(2000);
             });
+
+            modelBuilder.Entity<Drawing>(entity =>
+            {
+                entity.HasKey(e => e.Id);
+                entity.Property(e => e.DrawingNumber).HasMaxLength(100);
+                entity.Property(e => e.Title).HasMaxLength(200);
+                entity.Property(e => e.PdfContentHash).HasMaxLength(64);
+                entity.HasIndex(e => e.DrawingNumber).IsUnique();
+            });
         }
     }
 }

FabWorks.Core/Migrations/20260220125334_AddDrawingEntity.Designer.cs

@@ -0,0 +1,325 @@
+// <auto-generated />
+using System;
+using FabWorks.Core.Data;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Metadata;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+
+#nullable disable
+
+namespace FabWorks.Core.Migrations
+{
+    [DbContext(typeof(FabWorksDbContext))]
+    [Migration("20260220125334_AddDrawingEntity")]
+    partial class AddDrawingEntity
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasAnnotation("ProductVersion", "8.0.11")
+                .HasAnnotation("Relational:MaxIdentifierLength", 128);
+
+            SqlServerModelBuilderExtensions.UseIdentityColumns(modelBuilder);
+
+            modelBuilder.Entity("FabWorks.Core.Models.BomItem", b =>
+                {
+                    b.Property<int>("ID")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("int");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<int>("ID"));
+
+                    b.Property<string>("ConfigurationName")
+                        .HasMaxLength(100)
+                        .HasColumnType("nvarchar(100)");
+
+                    b.Property<string>("Description")
+                        .HasMaxLength(500)
+                        .HasColumnType("nvarchar(500)");
+
+                    b.Property<int>("ExportRecordId")
+                        .HasColumnType("int");
+
+                    b.Property<string>("ItemNo")
+                        .HasMaxLength(50)
+                        .HasColumnType("nvarchar(50)");
+
+                    b.Property<string>("Material")
+                        .HasMaxLength(100)
+                        .HasColumnType("nvarchar(100)");
+
+                    b.Property<string>("PartName")
+                        .HasMaxLength(200)
+                        .HasColumnType("nvarchar(200)");
+
+                    b.Property<string>("PartNo")
+                        .HasMaxLength(100)
+                        .HasColumnType("nvarchar(100)");
+
+                    b.Property<int?>("Qty")
+                        .HasColumnType("int");
+
+                    b.Property<int>("SortOrder")
+                        .HasColumnType("int");
+
+                    b.Property<int?>("TotalQty")
+                        .HasColumnType("int");
+
+                    b.HasKey("ID");
+
+                    b.HasIndex("ExportRecordId");
+
+                    b.ToTable("BomItems");
+                });
+
+            modelBuilder.Entity("FabWorks.Core.Models.CutTemplate", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("int");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<int>("Id"));
+
+                    b.Property<int>("BomItemId")
+                        .HasColumnType("int");
+
+                    b.Property<string>("ContentHash")
+                        .HasMaxLength(64)
+                        .HasColumnType("nvarchar(64)");
+
+                    b.Property<string>("CutTemplateName")
+                        .HasMaxLength(100)
+                        .HasColumnType("nvarchar(100)");
+
+                    b.Property<double?>("DefaultBendRadius")
+                        .HasColumnType("float");
+
+                    b.Property<string>("DxfFilePath")
+                        .HasMaxLength(500)
+                        .HasColumnType("nvarchar(500)");
+
+                    b.Property<double?>("KFactor")
+                        .HasColumnType("float");
+
+                    b.Property<int>("Revision")
+                        .HasColumnType("int");
+
+                    b.Property<double?>("Thickness")
+                        .HasColumnType("float");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("BomItemId")
+                        .IsUnique();
+
+                    b.ToTable("CutTemplates");
+                });
+
+            modelBuilder.Entity("FabWorks.Core.Models.Drawing", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("int");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<int>("Id"));
+
+                    b.Property<string>("DrawingNumber")
+                        .HasMaxLength(100)
+                        .HasColumnType("nvarchar(100)");
+
+                    b.Property<string>("PdfContentHash")
+                        .HasMaxLength(64)
+                        .HasColumnType("nvarchar(64)");
+
+                    b.Property<int>("Revision")
+                        .HasColumnType("int");
+
+                    b.Property<string>("Title")
+                        .HasMaxLength(200)
+                        .HasColumnType("nvarchar(200)");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("DrawingNumber")
+                        .IsUnique()
+                        .HasFilter("[DrawingNumber] IS NOT NULL");
+
+                    b.ToTable("Drawings");
+                });
+
+            modelBuilder.Entity("FabWorks.Core.Models.ExportRecord", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("int");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<int>("Id"));
+
+                    b.Property<int?>("DrawingId")
+                        .HasColumnType("int");
+
+                    b.Property<string>("DrawingNo")
+                        .HasMaxLength(50)
+                        .HasColumnType("nvarchar(50)");
+
+                    b.Property<string>("DrawingNumber")
+                        .HasMaxLength(100)
+                        .HasColumnType("nvarchar(100)");
+
+                    b.Property<string>("EquipmentNo")
+                        .HasMaxLength(50)
+                        .HasColumnType("nvarchar(50)");
+
+                    b.Property<DateTime>("ExportedAt")
+                        .HasColumnType("datetime2");
+
+                    b.Property<string>("ExportedBy")
+                        .HasMaxLength(100)
+                        .HasColumnType("nvarchar(100)");
+
+                    b.Property<string>("OutputFolder")
+                        .HasMaxLength(500)
+                        .HasColumnType("nvarchar(500)");
+
+                    b.Property<string>("PdfContentHash")
+                        .HasMaxLength(64)
+                        .HasColumnType("nvarchar(64)");
+
+                    b.Property<string>("SourceFilePath")
+                        .HasMaxLength(500)
+                        .HasColumnType("nvarchar(500)");
+
+                    b.Property<string>("Title")
+                        .HasMaxLength(200)
+                        .HasColumnType("nvarchar(200)");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("DrawingId");
+
+                    b.ToTable("ExportRecords");
+                });
+
+            modelBuilder.Entity("FabWorks.Core.Models.FormProgram", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("int");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<int>("Id"));
+
+                    b.Property<int>("BendCount")
+                        .HasColumnType("int");
+
+                    b.Property<int>("BomItemId")
+                        .HasColumnType("int");
+
+                    b.Property<string>("ContentHash")
+                        .HasMaxLength(64)
+                        .HasColumnType("nvarchar(64)");
+
+                    b.Property<double?>("KFactor")
+                        .HasColumnType("float");
+
+                    b.Property<string>("LowerToolNames")
+                        .HasMaxLength(500)
+                        .HasColumnType("nvarchar(500)");
+
+                    b.Property<string>("MaterialType")
+                        .HasMaxLength(50)
+                        .HasColumnType("nvarchar(50)");
+
+                    b.Property<string>("ProgramFilePath")
+                        .HasMaxLength(500)
+                        .HasColumnType("nvarchar(500)");
+
+                    b.Property<string>("ProgramName")
+                        .HasMaxLength(200)
+                        .HasColumnType("nvarchar(200)");
+
+                    b.Property<string>("SetupNotes")
+                        .HasMaxLength(2000)
+                        .HasColumnType("nvarchar(2000)");
+
+                    b.Property<double?>("Thickness")
+                        .HasColumnType("float");
+
+                    b.Property<string>("UpperToolNames")
+                        .HasMaxLength(500)
+                        .HasColumnType("nvarchar(500)");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("BomItemId")
+                        .IsUnique();
+
+                    b.ToTable("FormPrograms");
+                });
+
+            modelBuilder.Entity("FabWorks.Core.Models.BomItem", b =>
+                {
+                    b.HasOne("FabWorks.Core.Models.ExportRecord", "ExportRecord")
+                        .WithMany("BomItems")
+                        .HasForeignKey("ExportRecordId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("ExportRecord");
+                });
+
+            modelBuilder.Entity("FabWorks.Core.Models.CutTemplate", b =>
+                {
+                    b.HasOne("FabWorks.Core.Models.BomItem", "BomItem")
+                        .WithOne("CutTemplate")
+                        .HasForeignKey("FabWorks.Core.Models.CutTemplate", "BomItemId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("BomItem");
+                });
+
+            modelBuilder.Entity("FabWorks.Core.Models.ExportRecord", b =>
+                {
+                    b.HasOne("FabWorks.Core.Models.Drawing", "Drawing")
+                        .WithMany("ExportRecords")
+                        .HasForeignKey("DrawingId")
+                        .OnDelete(DeleteBehavior.SetNull);
+
+                    b.Navigation("Drawing");
+                });
+
+            modelBuilder.Entity("FabWorks.Core.Models.FormProgram", b =>
+                {
+                    b.HasOne("FabWorks.Core.Models.BomItem", "BomItem")
+                        .WithOne("FormProgram")
+                        .HasForeignKey("FabWorks.Core.Models.FormProgram", "BomItemId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("BomItem");
+                });
+
+            modelBuilder.Entity("FabWorks.Core.Models.BomItem", b =>
+                {
+                    b.Navigation("CutTemplate");
+
+                    b.Navigation("FormProgram");
+                });
+
+            modelBuilder.Entity("FabWorks.Core.Models.Drawing", b =>
+                {
+                    b.Navigation("ExportRecords");
+                });
+
+            modelBuilder.Entity("FabWorks.Core.Models.ExportRecord", b =>
+                {
+                    b.Navigation("BomItems");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}

FabWorks.Core/Migrations/20260220125334_AddDrawingEntity.cs

@@ -0,0 +1,75 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace FabWorks.Core.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddDrawingEntity : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<int>(
+                name: "DrawingId",
+                table: "ExportRecords",
+                type: "int",
+                nullable: true);
+
+            migrationBuilder.CreateTable(
+                name: "Drawings",
+                columns: table => new
+                {
+                    Id = table.Column<int>(type: "int", nullable: false)
+                        .Annotation("SqlServer:Identity", "1, 1"),
+                    DrawingNumber = table.Column<string>(type: "nvarchar(100)", maxLength: 100, nullable: true),
+                    Title = table.Column<string>(type: "nvarchar(200)", maxLength: 200, nullable: true),
+                    PdfContentHash = table.Column<string>(type: "nvarchar(64)", maxLength: 64, nullable: true),
+                    Revision = table.Column<int>(type: "int", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_Drawings", x => x.Id);
+                });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_ExportRecords_DrawingId",
+                table: "ExportRecords",
+                column: "DrawingId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Drawings_DrawingNumber",
+                table: "Drawings",
+                column: "DrawingNumber",
+                unique: true,
+                filter: "[DrawingNumber] IS NOT NULL");
+
+            migrationBuilder.AddForeignKey(
+                name: "FK_ExportRecords_Drawings_DrawingId",
+                table: "ExportRecords",
+                column: "DrawingId",
+                principalTable: "Drawings",
+                principalColumn: "Id",
+                onDelete: ReferentialAction.SetNull);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropForeignKey(
+                name: "FK_ExportRecords_Drawings_DrawingId",
+                table: "ExportRecords");
+
+            migrationBuilder.DropTable(
+                name: "Drawings");
+
+            migrationBuilder.DropIndex(
+                name: "IX_ExportRecords_DrawingId",
+                table: "ExportRecords");
+
+            migrationBuilder.DropColumn(
+                name: "DrawingId",
+                table: "ExportRecords");
+        }
+    }
+}

FabWorks.Core/Migrations/20260220130029_SeedDrawingsFromExistingExports.Designer.cs

@@ -0,0 +1,325 @@
+// <auto-generated />
+using System;
+using FabWorks.Core.Data;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Metadata;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+
+#nullable disable
+
+namespace FabWorks.Core.Migrations
+{
+    [DbContext(typeof(FabWorksDbContext))]
+    [Migration("20260220130029_SeedDrawingsFromExistingExports")]
+    partial class SeedDrawingsFromExistingExports
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasAnnotation("ProductVersion", "8.0.11")
+                .HasAnnotation("Relational:MaxIdentifierLength", 128);
+
+            SqlServerModelBuilderExtensions.UseIdentityColumns(modelBuilder);
+
+            modelBuilder.Entity("FabWorks.Core.Models.BomItem", b =>
+                {
+                    b.Property<int>("ID")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("int");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<int>("ID"));
+
+                    b.Property<string>("ConfigurationName")
+                        .HasMaxLength(100)
+                        .HasColumnType("nvarchar(100)");
+
+                    b.Property<string>("Description")
+                        .HasMaxLength(500)
+                        .HasColumnType("nvarchar(500)");
+
+                    b.Property<int>("ExportRecordId")
+                        .HasColumnType("int");
+
+                    b.Property<string>("ItemNo")
+                        .HasMaxLength(50)
+                        .HasColumnType("nvarchar(50)");
+
+                    b.Property<string>("Material")
+                        .HasMaxLength(100)
+                        .HasColumnType("nvarchar(100)");
+
+                    b.Property<string>("PartName")
+                        .HasMaxLength(200)
+                        .HasColumnType("nvarchar(200)");
+
+                    b.Property<string>("PartNo")
+                        .HasMaxLength(100)
+                        .HasColumnType("nvarchar(100)");
+
+                    b.Property<int?>("Qty")
+                        .HasColumnType("int");
+
+                    b.Property<int>("SortOrder")
+                        .HasColumnType("int");
+
+                    b.Property<int?>("TotalQty")
+                        .HasColumnType("int");
+
+                    b.HasKey("ID");
+
+                    b.HasIndex("ExportRecordId");
+
+                    b.ToTable("BomItems");
+                });
+
+            modelBuilder.Entity("FabWorks.Core.Models.CutTemplate", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("int");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<int>("Id"));
+
+                    b.Property<int>("BomItemId")
+                        .HasColumnType("int");
+
+                    b.Property<string>("ContentHash")
+                        .HasMaxLength(64)
+                        .HasColumnType("nvarchar(64)");
+
+                    b.Property<string>("CutTemplateName")
+                        .HasMaxLength(100)
+                        .HasColumnType("nvarchar(100)");
+
+                    b.Property<double?>("DefaultBendRadius")
+                        .HasColumnType("float");
+
+                    b.Property<string>("DxfFilePath")
+                        .HasMaxLength(500)
+                        .HasColumnType("nvarchar(500)");
+
+                    b.Property<double?>("KFactor")
+                        .HasColumnType("float");
+
+                    b.Property<int>("Revision")
+                        .HasColumnType("int");
+
+                    b.Property<double?>("Thickness")
+                        .HasColumnType("float");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("BomItemId")
+                        .IsUnique();
+
+                    b.ToTable("CutTemplates");
+                });
+
+            modelBuilder.Entity("FabWorks.Core.Models.Drawing", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("int");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<int>("Id"));
+
+                    b.Property<string>("DrawingNumber")
+                        .HasMaxLength(100)
+                        .HasColumnType("nvarchar(100)");
+
+                    b.Property<string>("PdfContentHash")
+                        .HasMaxLength(64)
+                        .HasColumnType("nvarchar(64)");
+
+                    b.Property<int>("Revision")
+                        .HasColumnType("int");
+
+                    b.Property<string>("Title")
+                        .HasMaxLength(200)
+                        .HasColumnType("nvarchar(200)");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("DrawingNumber")
+                        .IsUnique()
+                        .HasFilter("[DrawingNumber] IS NOT NULL");
+
+                    b.ToTable("Drawings");
+                });
+
+            modelBuilder.Entity("FabWorks.Core.Models.ExportRecord", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("int");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<int>("Id"));
+
+                    b.Property<int?>("DrawingId")
+                        .HasColumnType("int");
+
+                    b.Property<string>("DrawingNo")
+                        .HasMaxLength(50)
+                        .HasColumnType("nvarchar(50)");
+
+                    b.Property<string>("DrawingNumber")
+                        .HasMaxLength(100)
+                        .HasColumnType("nvarchar(100)");
+
+                    b.Property<string>("EquipmentNo")
+                        .HasMaxLength(50)
+                        .HasColumnType("nvarchar(50)");
+
+                    b.Property<DateTime>("ExportedAt")
+                        .HasColumnType("datetime2");
+
+                    b.Property<string>("ExportedBy")
+                        .HasMaxLength(100)
+                        .HasColumnType("nvarchar(100)");
+
+                    b.Property<string>("OutputFolder")
+                        .HasMaxLength(500)
+                        .HasColumnType("nvarchar(500)");
+
+                    b.Property<string>("PdfContentHash")
+                        .HasMaxLength(64)
+                        .HasColumnType("nvarchar(64)");
+
+                    b.Property<string>("SourceFilePath")
+                        .HasMaxLength(500)
+                        .HasColumnType("nvarchar(500)");
+
+                    b.Property<string>("Title")
+                        .HasMaxLength(200)
+                        .HasColumnType("nvarchar(200)");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("DrawingId");
+
+                    b.ToTable("ExportRecords");
+                });
+
+            modelBuilder.Entity("FabWorks.Core.Models.FormProgram", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("int");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<int>("Id"));
+
+                    b.Property<int>("BendCount")
+                        .HasColumnType("int");
+
+                    b.Property<int>("BomItemId")
+                        .HasColumnType("int");
+
+                    b.Property<string>("ContentHash")
+                        .HasMaxLength(64)
+                        .HasColumnType("nvarchar(64)");
+
+                    b.Property<double?>("KFactor")
+                        .HasColumnType("float");
+
+                    b.Property<string>("LowerToolNames")
+                        .HasMaxLength(500)
+                        .HasColumnType("nvarchar(500)");
+
+                    b.Property<string>("MaterialType")
+                        .HasMaxLength(50)
+                        .HasColumnType("nvarchar(50)");
+
+                    b.Property<string>("ProgramFilePath")
+                        .HasMaxLength(500)
+                        .HasColumnType("nvarchar(500)");
+
+                    b.Property<string>("ProgramName")
+                        .HasMaxLength(200)
+                        .HasColumnType("nvarchar(200)");
+
+                    b.Property<string>("SetupNotes")
+                        .HasMaxLength(2000)
+                        .HasColumnType("nvarchar(2000)");
+
+                    b.Property<double?>("Thickness")
+                        .HasColumnType("float");
+
+                    b.Property<string>("UpperToolNames")
+                        .HasMaxLength(500)
+                        .HasColumnType("nvarchar(500)");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("BomItemId")
+                        .IsUnique();
+
+                    b.ToTable("FormPrograms");
+                });
+
+            modelBuilder.Entity("FabWorks.Core.Models.BomItem", b =>
+                {
+                    b.HasOne("FabWorks.Core.Models.ExportRecord", "ExportRecord")
+                        .WithMany("BomItems")
+                        .HasForeignKey("ExportRecordId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("ExportRecord");
+                });
+
+            modelBuilder.Entity("FabWorks.Core.Models.CutTemplate", b =>
+                {
+                    b.HasOne("FabWorks.Core.Models.BomItem", "BomItem")
+                        .WithOne("CutTemplate")
+                        .HasForeignKey("FabWorks.Core.Models.CutTemplate", "BomItemId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("BomItem");
+                });
+
+            modelBuilder.Entity("FabWorks.Core.Models.ExportRecord", b =>
+                {
+                    b.HasOne("FabWorks.Core.Models.Drawing", "Drawing")
+                        .WithMany("ExportRecords")
+                        .HasForeignKey("DrawingId")
+                        .OnDelete(DeleteBehavior.SetNull);
+
+                    b.Navigation("Drawing");
+                });
+
+            modelBuilder.Entity("FabWorks.Core.Models.FormProgram", b =>
+                {
+                    b.HasOne("FabWorks.Core.Models.BomItem", "BomItem")
+                        .WithOne("FormProgram")
+                        .HasForeignKey("FabWorks.Core.Models.FormProgram", "BomItemId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("BomItem");
+                });
+
+            modelBuilder.Entity("FabWorks.Core.Models.BomItem", b =>
+                {
+                    b.Navigation("CutTemplate");
+
+                    b.Navigation("FormProgram");
+                });
+
+            modelBuilder.Entity("FabWorks.Core.Models.Drawing", b =>
+                {
+                    b.Navigation("ExportRecords");
+                });
+
+            modelBuilder.Entity("FabWorks.Core.Models.ExportRecord", b =>
+                {
+                    b.Navigation("BomItems");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}

FabWorks.Core/Migrations/20260220130029_SeedDrawingsFromExistingExports.cs

@@ -0,0 +1,51 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace FabWorks.Core.Migrations
+{
+    /// <inheritdoc />
+    public partial class SeedDrawingsFromExistingExports : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            // Create Drawing records from existing ExportRecords (latest hash per DrawingNumber)
+            migrationBuilder.Sql(@"
+                INSERT INTO Drawings (DrawingNumber, Title, PdfContentHash, Revision)
+                SELECT
+                    sub.DrawingNumber,
+                    sub.Title,
+                    sub.PdfContentHash,
+                    1
+                FROM (
+                    SELECT
+                        e.DrawingNumber,
+                        e.Title,
+                        e.PdfContentHash,
+                        ROW_NUMBER() OVER (PARTITION BY e.DrawingNumber ORDER BY e.Id DESC) AS rn
+                    FROM ExportRecords e
+                    WHERE e.DrawingNumber IS NOT NULL
+                      AND e.PdfContentHash IS NOT NULL
+                ) sub
+                WHERE sub.rn = 1;
+            ");
+
+            // Link ExportRecords to their Drawing
+            migrationBuilder.Sql(@"
+                UPDATE er
+                SET er.DrawingId = d.Id
+                FROM ExportRecords er
+                INNER JOIN Drawings d ON d.DrawingNumber = er.DrawingNumber
+                WHERE er.PdfContentHash IS NOT NULL;
+            ");
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.Sql("UPDATE ExportRecords SET DrawingId = NULL;");
+            migrationBuilder.Sql("DELETE FROM Drawings;");
+        }
+    }
+}

FabWorks.Core/Migrations/FabWorksDbContextModelSnapshot.cs

@@ -116,6 +116,38 @@ namespace FabWorks.Core.Migrations
                     b.ToTable("CutTemplates");
                 });
 
+            modelBuilder.Entity("FabWorks.Core.Models.Drawing", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("int");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<int>("Id"));
+
+                    b.Property<string>("DrawingNumber")
+                        .HasMaxLength(100)
+                        .HasColumnType("nvarchar(100)");
+
+                    b.Property<string>("PdfContentHash")
+                        .HasMaxLength(64)
+                        .HasColumnType("nvarchar(64)");
+
+                    b.Property<int>("Revision")
+                        .HasColumnType("int");
+
+                    b.Property<string>("Title")
+                        .HasMaxLength(200)
+                        .HasColumnType("nvarchar(200)");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("DrawingNumber")
+                        .IsUnique()
+                        .HasFilter("[DrawingNumber] IS NOT NULL");
+
+                    b.ToTable("Drawings");
+                });
+
             modelBuilder.Entity("FabWorks.Core.Models.ExportRecord", b =>
                 {
                     b.Property<int>("Id")
@@ -124,6 +156,9 @@ namespace FabWorks.Core.Migrations
 
                     SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<int>("Id"));
 
+                    b.Property<int?>("DrawingId")
+                        .HasColumnType("int");
+
                     b.Property<string>("DrawingNo")
                         .HasMaxLength(50)
                         .HasColumnType("nvarchar(50)");
@@ -161,6 +196,8 @@ namespace FabWorks.Core.Migrations
 
                     b.HasKey("Id");
 
+                    b.HasIndex("DrawingId");
+
                     b.ToTable("ExportRecords");
                 });
 
@@ -242,6 +279,16 @@ namespace FabWorks.Core.Migrations
                     b.Navigation("BomItem");
                 });
 
+            modelBuilder.Entity("FabWorks.Core.Models.ExportRecord", b =>
+                {
+                    b.HasOne("FabWorks.Core.Models.Drawing", "Drawing")
+                        .WithMany("ExportRecords")
+                        .HasForeignKey("DrawingId")
+                        .OnDelete(DeleteBehavior.SetNull);
+
+                    b.Navigation("Drawing");
+                });
+
             modelBuilder.Entity("FabWorks.Core.Models.FormProgram", b =>
                 {
                     b.HasOne("FabWorks.Core.Models.BomItem", "BomItem")
@@ -260,6 +307,11 @@ namespace FabWorks.Core.Migrations
                     b.Navigation("FormProgram");
                 });
 
+            modelBuilder.Entity("FabWorks.Core.Models.Drawing", b =>
+                {
+                    b.Navigation("ExportRecords");
+                });
+
             modelBuilder.Entity("FabWorks.Core.Models.ExportRecord", b =>
                 {
                     b.Navigation("BomItems");

FabWorks.Core/Models/Drawing.cs

@@ -0,0 +1,15 @@
+using System.Collections.Generic;
+
+namespace FabWorks.Core.Models
+{
+    public class Drawing
+    {
+        public int Id { get; set; }
+        public string DrawingNumber { get; set; }
+        public string Title { get; set; }
+        public string PdfContentHash { get; set; }
+        public int Revision { get; set; } = 1;
+
+        public virtual ICollection<ExportRecord> ExportRecords { get; set; } = new List<ExportRecord>();
+    }
+}

FabWorks.Core/Models/ExportRecord.cs

@@ -16,6 +16,9 @@ namespace FabWorks.Core.Models
         public string ExportedBy { get; set; }
         public string PdfContentHash { get; set; }
 
+        public int? DrawingId { get; set; }
+        public virtual Drawing Drawing { get; set; }
+
         public virtual ICollection<BomItem> BomItems { get; set; } = new List<BomItem>();
     }
 }

docs/plans/2026-02-17-autofill-from-export-history-design.md

@@ -0,0 +1,32 @@
+# Auto-fill Equipment/Drawing from Export History
+
+## Problem
+
+When a SolidWorks file is opened that doesn't match the `DrawingInfo` regex (e.g., `Conveyor Frame.sldasm` instead of `5028 A02 Conveyor.slddrw`), the equipment and drawing number dropdowns are left empty even though the file may have been exported before with known values.
+
+## Decision
+
+- **Lookup key:** SolidWorks source file path (`ActiveDocument.FilePath`)
+- **Storage:** Query the existing `ExportRecords` table (no new table or migration)
+- **Priority:** Database lookup first; fall back to title regex parse if no history found
+
+## Design
+
+### Modify `UpdateActiveDocumentDisplay()` in `MainForm.cs`
+
+When the active document changes:
+
+1. Query the DB for the most recent `ExportRecord` where `SourceFilePath` matches `activeDoc.FilePath` (case-insensitive)
+2. If found, parse the stored `DrawingNumber` via `DrawingInfo.Parse()` and auto-fill equipment/drawing dropdowns
+3. If not found, fall back to current behavior: `DrawingInfo.Parse(activeDoc.Title)`
+
+### What doesn't change
+
+- No schema changes, no new migration
+- Equipment/drawing dropdowns still populated with historical values in `InitializeDrawingDropdowns()`
+- Export flow untouched
+
+### Error handling
+
+- DB query wrapped in try/catch so failures don't break the UI
+- Case-insensitive path comparison (Windows paths are case-insensitive)