feat: move revision tracking to ExportRecord, add perceptual hash comparison, cut list modal, and auto-start API

- Move Revision from Drawing to ExportRecord so each export captures its own revision snapshot
- Add Hamming distance comparison for perceptual hashes (tolerance of 10 bits) to avoid false revision bumps
- Replace CoenM.ImageHash with inline DifferenceHash impl (compatible with ImageSharp 3.x)
- Increase PDF render DPI from 72 to 150 for better hash fidelity
- Add download-dxfs-by-drawing endpoint for cross-export DXF zip downloads
- Prefix DXF filenames with equipment number when no drawing number is present
- Pass original filename to storage service for standalone part exports
- Auto-start FabWorks.Api from ExportDXF client if not already running
- Add cut list modal with copy-to-clipboard in the web UI
- Update PDF hash on existing export records after upload
- Bump static asset cache versions to v3

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

FabWorks.Api/Controllers/ExportsController.cs

@@ -1,4 +1,6 @@
+using System.Globalization;
 using System.IO.Compression;
+using System.Numerics;
 using FabWorks.Api.DTOs;
 using FabWorks.Api.Services;
 using FabWorks.Core.Data;
@@ -215,8 +217,9 @@ namespace FabWorks.Api.Controllers
 
             if (!string.IsNullOrEmpty(record.DrawingNumber) && !string.IsNullOrEmpty(request.PdfContentHash))
             {
-                var drawing = await ResolveDrawingAsync(record.DrawingNumber, record.Title, request.PdfContentHash);
-                record.DrawingId = drawing.Id;
+                var (drawing, revision) = await ResolveDrawingAsync(record.DrawingNumber, record.Title, request.PdfContentHash);
+                record.Drawing = drawing;
+                record.DrawingRevision = revision;
             }
 
             await _db.SaveChangesAsync();
@@ -224,36 +227,42 @@ namespace FabWorks.Api.Controllers
             return NoContent();
         }
 
-        private async Task<Drawing> ResolveDrawingAsync(string drawingNumber, string title, string pdfContentHash)
+        private async Task<(Drawing drawing, int revision)> ResolveDrawingAsync(string drawingNumber, string title, string pdfContentHash)
         {
             var drawing = await _db.Drawings
                 .FirstOrDefaultAsync(d => d.DrawingNumber == drawingNumber);
 
+            // Get the highest revision recorded for this drawing across all exports
+            var lastRevision = await _db.ExportRecords
+                .Where(r => r.DrawingNumber == drawingNumber && r.DrawingRevision != null)
+                .OrderByDescending(r => r.DrawingRevision)
+                .Select(r => r.DrawingRevision)
+                .FirstOrDefaultAsync() ?? 0;
+
             if (drawing == null)
             {
                 drawing = new Drawing
                 {
                     DrawingNumber = drawingNumber,
                     Title = title,
-                    PdfContentHash = pdfContentHash,
-                    Revision = 1
+                    PdfContentHash = pdfContentHash
                 };
                 _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, 1);
             }
 
-            return drawing;
+            if (!string.IsNullOrEmpty(title))
+                drawing.Title = title;
+
+            if (ArePerceptualHashesSimilar(drawing.PdfContentHash, pdfContentHash))
+            {
+                // Hash unchanged — keep same revision
+                return (drawing, lastRevision == 0 ? 1 : lastRevision);
+            }
+
+            // Hash changed — bump revision and update stored hash
+            drawing.PdfContentHash = pdfContentHash;
+            return (drawing, lastRevision + 1);
         }
 
         [HttpGet("previous-cut-template")]
@@ -316,6 +325,37 @@ namespace FabWorks.Api.Controllers
 
             if (dxfItems.Count == 0) return NotFound("No DXF files for this export.");
 
+            var zipName = $"{record.DrawingNumber ?? $"Export-{id}"} DXFs.zip";
+            return BuildDxfZip(dxfItems, zipName);
+        }
+
+        [HttpGet("download-dxfs")]
+        public async Task<IActionResult> DownloadDxfsByDrawing([FromQuery] string drawingNumber)
+        {
+            if (string.IsNullOrEmpty(drawingNumber))
+                return BadRequest("drawingNumber is required.");
+
+            var dxfItems = await _db.BomItems
+                .Include(b => b.CutTemplate)
+                .Where(b => b.ExportRecord.DrawingNumber == drawingNumber
+                         && b.CutTemplate != null
+                         && b.CutTemplate.ContentHash != null)
+                .ToListAsync();
+
+            if (dxfItems.Count == 0) return NotFound("No DXF files for this drawing.");
+
+            // Deduplicate by content hash (keep latest)
+            dxfItems = dxfItems
+                .GroupBy(b => b.CutTemplate.ContentHash)
+                .Select(g => g.Last())
+                .ToList();
+
+            var zipName = $"{drawingNumber} DXFs.zip";
+            return BuildDxfZip(dxfItems, zipName);
+        }
+
+        private FileResult BuildDxfZip(List<BomItem> dxfItems, string zipName)
+        {
             var ms = new MemoryStream();
             using (var zip = new ZipArchive(ms, ZipArchiveMode.Create, leaveOpen: true))
             {
@@ -341,16 +381,41 @@ namespace FabWorks.Api.Controllers
 
                     var entry = zip.CreateEntry(fileName, CompressionLevel.Fastest);
                     using var entryStream = entry.Open();
-                    await blobStream.CopyToAsync(entryStream);
+                    blobStream.CopyTo(entryStream);
                     blobStream.Dispose();
                 }
             }
 
             ms.Position = 0;
-            var zipName = $"{record.DrawingNumber ?? $"Export-{id}"} DXFs.zip";
             return File(ms, "application/zip", zipName);
         }
 
+        /// <summary>
+        /// Compares two perceptual hashes using Hamming distance.
+        /// Perceptual hashes (16 hex chars / 64 bits) are compared with a tolerance
+        /// of up to 10 differing bits (~84% similarity). SHA256 fallback hashes
+        /// (64 hex chars) use exact comparison.
+        /// </summary>
+        private static bool ArePerceptualHashesSimilar(string hash1, string hash2)
+        {
+            if (hash1 == hash2) return true;
+            if (string.IsNullOrEmpty(hash1) || string.IsNullOrEmpty(hash2)) return false;
+
+            // Perceptual hashes are 16 hex chars (64-bit DifferenceHash)
+            // SHA256 fallback hashes are 64 hex chars — require exact match
+            if (hash1.Length != 16 || hash2.Length != 16)
+                return false;
+
+            if (ulong.TryParse(hash1, NumberStyles.HexNumber, CultureInfo.InvariantCulture, out var h1) &&
+                ulong.TryParse(hash2, NumberStyles.HexNumber, CultureInfo.InvariantCulture, out var h2))
+            {
+                var hammingDistance = BitOperations.PopCount(h1 ^ h2);
+                return hammingDistance <= 10;
+            }
+
+            return false;
+        }
+
         private static ExportDetailDto MapToDto(ExportRecord r) => new()
         {
             Id = r.Id,

FabWorks.Api/Controllers/FileBrowserController.cs

@@ -88,7 +88,7 @@ namespace FabWorks.Api.Controllers
                         r.DrawingNumber,
                         r.PdfContentHash,
                         r.ExportedAt,
-                        DrawingRevision = r.Drawing != null ? (int?)r.Drawing.Revision : null
+                        r.DrawingRevision
                     });
 
                 if (!string.IsNullOrWhiteSpace(search))

FabWorks.Api/Controllers/FilesController.cs

@@ -30,7 +30,7 @@ namespace FabWorks.Api.Controllers
                 return BadRequest("No file uploaded.");
 
             using var stream = file.OpenReadStream();
-            var result = await _fileStorage.StoreDxfAsync(stream, equipment, drawingNo, itemNo, contentHash);
+            var result = await _fileStorage.StoreDxfAsync(stream, equipment, drawingNo, itemNo, contentHash, file.FileName);
 
             return Ok(new FileUploadResponse
             {

FabWorks.Api/Services/FileStorageService.cs

@@ -16,7 +16,7 @@ namespace FabWorks.Api.Services
     public interface IFileStorageService
     {
         string OutputFolder { get; }
-        Task<FileUploadResult> StoreDxfAsync(Stream stream, string equipment, string drawingNo, string itemNo, string contentHash);
+        Task<FileUploadResult> StoreDxfAsync(Stream stream, string equipment, string drawingNo, string itemNo, string contentHash, string originalFileName = null);
         Task<FileUploadResult> StorePdfAsync(Stream stream, string equipment, string drawingNo, string contentHash, int? exportRecordId = null);
         Stream OpenBlob(string contentHash, string extension);
         bool BlobExists(string contentHash, string extension);
@@ -39,9 +39,9 @@ namespace FabWorks.Api.Services
                 Directory.CreateDirectory(blobRoot);
         }
 
-        public async Task<FileUploadResult> StoreDxfAsync(Stream stream, string equipment, string drawingNo, string itemNo, string contentHash)
+        public async Task<FileUploadResult> StoreDxfAsync(Stream stream, string equipment, string drawingNo, string itemNo, string contentHash, string originalFileName = null)
         {
-            var fileName = BuildDxfFileName(drawingNo, equipment, itemNo);
+            var fileName = BuildDxfFileName(drawingNo, equipment, itemNo, originalFileName);
 
             // Look up previous hash by drawing number + item number
             var drawingNumber = BuildDrawingNumber(equipment, drawingNo);
@@ -147,8 +147,16 @@ namespace FabWorks.Api.Services
             return drawingNo ?? "";
         }
 
-        private static string BuildDxfFileName(string drawingNo, string equipment, string itemNo)
+        private static string BuildDxfFileName(string drawingNo, string equipment, string itemNo, string originalFileName = null)
         {
+            // No drawing number: use the original filename from the client
+            if (string.IsNullOrEmpty(drawingNo) && !string.IsNullOrEmpty(originalFileName))
+            {
+                return originalFileName.EndsWith(".dxf", StringComparison.OrdinalIgnoreCase)
+                    ? originalFileName
+                    : originalFileName + ".dxf";
+            }
+
             var drawingNumber = BuildDrawingNumber(equipment, drawingNo);
             var paddedItem = (itemNo ?? "").PadLeft(2, '0');
             if (!string.IsNullOrEmpty(drawingNumber) && !string.IsNullOrEmpty(itemNo))

FabWorks.Api/wwwroot/css/styles.css

@@ -735,6 +735,85 @@ tbody tr:last-child td { border-bottom: none; }
 .equip-group.collapsed .equip-body { display: none; }
 .equip-group.collapsed .equip-header { border-radius: 6px; }
 
+/* ─── Modal ─── */
+.modal-overlay {
+    position: fixed;
+    inset: 0;
+    background: rgba(0, 0, 0, 0.35);
+    backdrop-filter: blur(4px);
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    z-index: 200;
+    animation: fadeIn 0.15s ease;
+}
+
+@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
+
+.modal-panel {
+    background: var(--surface);
+    border: 1px solid var(--border);
+    border-radius: 8px;
+    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.15);
+    width: 90%;
+    max-width: 640px;
+    max-height: 80vh;
+    display: flex;
+    flex-direction: column;
+    animation: fadeSlideIn 0.2s ease forwards;
+}
+
+.modal-header {
+    padding: 14px 18px;
+    border-bottom: 1px solid var(--border-subtle);
+    font-family: var(--font-display);
+    font-weight: 600;
+    font-size: 14px;
+    letter-spacing: 0.02em;
+    display: flex;
+    align-items: center;
+    gap: 10px;
+    text-transform: uppercase;
+    color: var(--text-secondary);
+}
+
+.modal-header svg { width: 16px; height: 16px; }
+
+.modal-body {
+    overflow-y: auto;
+    flex: 1;
+}
+
+.btn-green {
+    background: var(--green-dim);
+    color: var(--green);
+    border-color: rgba(6, 118, 71, 0.25);
+}
+
+.btn-green:hover {
+    background: rgba(6, 118, 71, 0.15);
+    border-color: rgba(6, 118, 71, 0.4);
+    color: var(--green);
+}
+
+/* ─── Toast ─── */
+.toast {
+    position: fixed;
+    bottom: 24px;
+    left: 50%;
+    transform: translateX(-50%);
+    background: var(--text);
+    color: #fff;
+    padding: 8px 20px;
+    border-radius: 4px;
+    font-family: var(--font-mono);
+    font-size: 13px;
+    z-index: 300;
+    animation: fadeSlideIn 0.2s ease, fadeOut 0.3s ease 2s forwards;
+}
+
+@keyframes fadeOut { to { opacity: 0; } }
+
 /* ─── Responsive ─── */
 @media (max-width: 768px) {
     .sidebar { display: none; }

FabWorks.Api/wwwroot/index.html

@@ -46,11 +46,11 @@
         <div class="page-content" id="page-content"></div>
     </div>
 
-    <script src="js/icons.js?v=2"></script>
-    <script src="js/helpers.js?v=2"></script>
-    <script src="js/components.js?v=2"></script>
-    <script src="js/pages.js?v=2"></script>
-    <script src="js/router.js?v=2"></script>
+    <script src="js/icons.js?v=3"></script>
+    <script src="js/helpers.js?v=3"></script>
+    <script src="js/components.js?v=3"></script>
+    <script src="js/pages.js?v=3"></script>
+    <script src="js/router.js?v=3"></script>
     <script>router.init();</script>
 </body>
 </html>

FabWorks.Api/wwwroot/js/components.js

@@ -58,3 +58,98 @@ function toggleBomRow(id) {
     row.style.display = visible ? 'none' : '';
     if (icon) icon.classList.toggle('open', !visible);
 }
+
+/* ─── Cut List Modal ─── */
+function showCutListModal(bomItems) {
+    const cutItems = bomItems.filter(b => b.cutTemplate);
+    if (cutItems.length === 0) {
+        showToast('No cut templates found');
+        return;
+    }
+
+    const rows = cutItems.map(b => {
+        const ct = b.cutTemplate;
+        const name = ct.cutTemplateName || ct.dxfFilePath?.split(/[/\\]/).pop()?.replace(/\.dxf$/i, '') || b.partName || '';
+        const qty = b.qty ?? '';
+        return { name, qty };
+    });
+
+    const tableRows = rows.map((r, i) => `
+        <tr style="animation: fadeSlideIn 0.15s ease ${0.02 * i}s forwards; opacity: 0">
+            <td style="font-family:var(--font-mono);font-weight:600">${esc(r.name)}</td>
+            <td style="font-family:var(--font-mono);text-align:center">${r.qty}</td>
+        </tr>`).join('');
+
+    // Remove existing modal if any
+    const existing = document.getElementById('cut-list-modal');
+    if (existing) existing.remove();
+
+    const modal = document.createElement('div');
+    modal.id = 'cut-list-modal';
+    modal.className = 'modal-overlay';
+    modal.innerHTML = `
+        <div class="modal-panel">
+            <div class="modal-header">
+                <span>${icons.laser} Cut List</span>
+                <span class="badge badge-count">${cutItems.length} templates</span>
+                <span style="margin-left:auto;display:flex;gap:6px">
+                    <button class="btn btn-cyan btn-sm" onclick="copyCutList()" id="copy-cut-list-btn">${icons.clipboard} Copy</button>
+                    <button class="btn btn-sm" onclick="closeCutListModal()">${icons.close}</button>
+                </span>
+            </div>
+            <div class="modal-body">
+                <table>
+                    <thead><tr>
+                        <th>Name</th>
+                        <th style="width:60px;text-align:center">Qty</th>
+                    </tr></thead>
+                    <tbody>${tableRows}</tbody>
+                </table>
+            </div>
+        </div>`;
+
+    document.body.appendChild(modal);
+    // Store data for copy
+    modal._cutData = rows;
+    // Close on backdrop click
+    modal.addEventListener('click', e => { if (e.target === modal) closeCutListModal(); });
+    // Close on Escape
+    modal._keyHandler = e => { if (e.key === 'Escape') closeCutListModal(); };
+    document.addEventListener('keydown', modal._keyHandler);
+}
+
+function closeCutListModal() {
+    const modal = document.getElementById('cut-list-modal');
+    if (!modal) return;
+    document.removeEventListener('keydown', modal._keyHandler);
+    modal.remove();
+}
+
+function copyCutList() {
+    const modal = document.getElementById('cut-list-modal');
+    if (!modal || !modal._cutData) return;
+
+    const text = modal._cutData.map(r => `${r.name}\t${r.qty}`).join('\n');
+
+    navigator.clipboard.writeText(text).then(() => {
+        const btn = document.getElementById('copy-cut-list-btn');
+        if (btn) {
+            btn.innerHTML = `${icons.check} Copied!`;
+            btn.classList.remove('btn-cyan');
+            btn.classList.add('btn-green');
+            setTimeout(() => {
+                btn.innerHTML = `${icons.clipboard} Copy`;
+                btn.classList.remove('btn-green');
+                btn.classList.add('btn-cyan');
+            }, 2000);
+        }
+    });
+}
+
+function showToast(msg) {
+    const t = document.createElement('div');
+    t.className = 'toast';
+    t.textContent = msg;
+    document.body.appendChild(t);
+    setTimeout(() => t.remove(), 2500);
+}

FabWorks.Api/wwwroot/js/icons.js

@@ -10,6 +10,9 @@ const icons = {
     laser: `<svg viewBox="0 0 16 16" fill="none" stroke="var(--cyan)" stroke-width="1.2"><circle cx="8" cy="8" r="2"/><path d="M8 2v3M8 11v3M2 8h3M11 8h3" opacity="0.5"/></svg>`,
     bend: `<svg viewBox="0 0 16 16" fill="none" stroke="var(--amber)" stroke-width="1.2"><path d="M3 13V7a4 4 0 0 1 4-4h6"/><polyline points="10 6 13 3 10 0" transform="translate(0,2)"/></svg>`,
     trash: `<svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><polyline points="3 6 5 6 21 6"/><path d="M19 6l-1 14a2 2 0 0 1-2 2H8a2 2 0 0 1-2-2L5 6"/><path d="M10 11v6"/><path d="M14 11v6"/><path d="M9 6V4a1 1 0 0 1 1-1h4a1 1 0 0 1 1 1v2"/></svg>`,
+    clipboard: `<svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><rect x="9" y="2" width="6" height="4" rx="1"/><path d="M9 2H7a2 2 0 0 0-2 2v16a2 2 0 0 0 2 2h10a2 2 0 0 0 2-2V4a2 2 0 0 0-2-2h-2"/><line x1="9" y1="12" x2="15" y2="12"/><line x1="9" y1="16" x2="15" y2="16"/></svg>`,
+    check: `<svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><polyline points="20 6 9 17 4 12"/></svg>`,
+    close: `<svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><line x1="18" y1="6" x2="6" y2="18"/><line x1="6" y1="6" x2="18" y2="18"/></svg>`,
 };
 
 function fileIcon(name) {

FabWorks.Api/wwwroot/js/pages.js

@@ -213,6 +213,9 @@ const pages = {
                 allBom = [...bomByItem.values()];
             }
 
+            // Store for cut list modal
+            window._currentBom = allBom;
+
             const bomRows = allBom.map((b, i) => {
                 const hasDetails = b.cutTemplate || b.formProgram;
                 const toggleId = `dbom-${b.id}`;
@@ -265,8 +268,12 @@ const pages = {
                         ${bomHeader}
                         <span class="badge badge-count">${allBom.length} items</span>
                         <span style="margin-left:auto;display:flex;gap:6px">
+                            ${dxfCount > 0 ? `<button class="btn btn-sm" onclick="showCutListModal(window._currentBom)">${icons.clipboard} Cut List</button>` : ''}
                             ${pdfHash ? `<a class="btn btn-amber btn-sm" href="/api/filebrowser/download?hash=${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>` : ''}
+                            ${dxfCount > 0 ? (singleExport
+                                ? `<a class="btn btn-cyan btn-sm" href="/api/exports/${activeExport.id}/download-dxfs">${icons.download} All DXFs</a>`
+                                : `<a class="btn btn-cyan btn-sm" href="/api/exports/download-dxfs?drawingNumber=${encodeURIComponent(drawingNumber)}">${icons.download} All DXFs</a>`
+                            ) : ''}
                         </span>
                     </div>
                     ${allBom.length ? `