fix(cutting): anchor near-corner entries to their native edge

Preserve reviewed cutting-start and plate-label commits; operator accepted A1-A4 and B1-B7. Excludes best-effort cutting and color trials.

.github/workflows/ci.yml

@@ -97,6 +97,11 @@ jobs:
             if ($LASTEXITCODE -ne 0) { $failed += $project }
           }
           if ($failed.Count -gt 0) { throw "Failed: $($failed -join ', ')" }
+      - name: Test acceptance evidence checker
+        run: python scripts/test_windows_acceptance.py -v
+      - name: Verify named Windows acceptance coverage
+        if: always()
+        run: python scripts/windows_acceptance.py --results TestResults
       - name: Upload test results
         if: always()
         uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4

.github/workflows/server-image.yml

@@ -114,7 +114,7 @@ jobs:
   publish:
     if: >-
       github.repository == 'ajisaacs/OpenNest' &&
-      (github.event_name == 'release' ||
+      ((github.event_name == 'release' && github.event.release.prerelease == false) ||
        (github.event_name == 'workflow_dispatch' && github.ref == 'refs/heads/master'))
     runs-on: ubuntu-latest
     timeout-minutes: 40

.github/workflows/windows-release.yml

@@ -49,6 +49,20 @@ jobs:
         run: |
           dotnet build OpenNest.sln -c Release
           if ($LASTEXITCODE -ne 0) { throw 'Solution build failed.' }
+      - name: Install pinned Poppler for PDF report tests
+        run: |
+          $zip = Join-Path $env:RUNNER_TEMP 'poppler-26.09.0.zip'
+          Invoke-WebRequest 'https://github.com/oschwartz10612/poppler-windows/releases/download/v26.09.0-0/Release-26.09.0-0.zip' -OutFile $zip
+          $actual = (Get-FileHash $zip -Algorithm SHA256).Hash.ToLowerInvariant()
+          if ($actual -ne '7a6f256a0ddf7536182246a5733331bf4677cbcc34f4663774947ad34556c8d0') { throw 'Poppler archive hash mismatch.' }
+          $destination = Join-Path $env:RUNNER_TEMP 'poppler-release-tests'
+          Expand-Archive $zip -DestinationPath $destination
+          $bin = Join-Path $destination 'poppler-26.09.0/Library/bin'
+          $tool = Join-Path $bin 'pdftotext.exe'
+          if (-not (Test-Path $tool)) { throw 'Pinned pdftotext.exe is missing.' }
+          & $tool -v
+          if ($LASTEXITCODE -ne 0) { throw 'Pinned pdftotext.exe cannot start.' }
+          $bin >> $env:GITHUB_PATH
       - name: Run all test projects on Windows
         # A test silent for 5 minutes is killed and named in the log, with a
         # mini dump in TestResults, instead of holding the runner until the

OpenNest.Api/NestRequestPlate.cs

@@ -5,6 +5,9 @@ namespace OpenNest.Api;
 /// <summary>One explicit physical-stock type for a whole nesting job.</summary>
 public class NestRequestPlate
 {
+    /// <summary>Positive per-sheet cost in common units; omit on every row for area scoring.</summary>
+    public double? Cost { get; init; }
+
     public string Id { get; init; }
     public Size Size { get; init; }
 

OpenNest.Api/NestResponse.cs

@@ -44,6 +44,7 @@ public class NestResponse
     public IReadOnlyList<NestPartFulfillment> Fulfillment { get; init; } = [];
     public IReadOnlyList<NestStockUsage> StockUsage { get; init; } = [];
     public IReadOnlyList<NestPlateStockMapping> PlateStockMappings { get; init; } = [];
+    public NestCostSummary Costs { get; init; }
     public Nest Nest { get; init; }
     public NestRequest Request { get; init; }
 
@@ -86,6 +87,7 @@ public class NestResponse
                     Fulfillment = Fulfillment is null
                         ? []
                         : new List<NestPartFulfillment>(Fulfillment),
+                    Costs = Costs,
                     StockUsage = StockUsage is null ? [] : new List<NestStockUsage>(StockUsage),
                     PlateStockMappings = PlateStockMappings is null
                         ? []
@@ -171,6 +173,7 @@ public class NestResponse
             Fulfillment = hasStatusMetadata ? archive.Fulfillment ?? [] : [],
             StockUsage = hasStatusMetadata ? archive.StockUsage ?? [] : [],
             PlateStockMappings = hasStatusMetadata ? archive.PlateStockMappings ?? [] : [],
+            Costs = archive.Costs,
             Nest = nest,
             Request = request,
         };
@@ -178,6 +181,7 @@ public class NestResponse
 
     private sealed class NestResponseArchiveDto
     {
+        public NestCostSummary Costs { get; init; }
         public int SchemaVersion { get; init; }
         public int SheetCount { get; init; }
         public double Utilization { get; init; }

OpenNest.Api/NestRunner.cs

@@ -28,6 +28,7 @@ public static class NestRunner
         if (requestParts.Count == 0)
             throw new ArgumentException("Request must contain at least one part.", nameof(request));
 
+        var stock = CreateStock(request);
         var sw = Stopwatch.StartNew();
         var parts = IdentifyParts(requestParts);
         var importedByPath = new Dictionary<string, Drawing>(StringComparer.Ordinal);
@@ -82,7 +83,6 @@ public static class NestRunner
             });
         }
 
-        var stock = CreateStock(request);
         var engineName = request.Engine ?? ResolvePlacementStrategy(request);
         var jobProgress = progress == null ? null : new JobProgressBridge(progress);
         var result = NestPipeline.Run(new NestPipelineRequest(
@@ -91,6 +91,9 @@ public static class NestRunner
         // API returns a detached proposal, not an acceptance/commit to a caller's nest.
         // Invalid but representable proposals retain every pose and carry explicit validation status.
         var nest = new Nest { Thickness = request.Thickness, Material = new Material(request.Material) };
+        if (request.Plates != null)
+            nest.PlateOptions = stock.Where(s => s.Quantity != 0).Select(s => new PlateOption
+            { Width = s.Size.Width, Length = s.Size.Length, Cost = s.Cost ?? 0 }).ToList();
         foreach (var item in items)
             nest.Drawings.Add(item.Drawing);
         foreach (var proposed in result.Plates)
@@ -144,6 +147,7 @@ public static class NestRunner
                 Violations = result.Violations,
                 Fulfillment = fulfillment,
                 StockUsage = usage,
+                Costs = result.CanKeep && result.IsValid ? NestCostSummary.FromAccepted(result) : null,
                 PlateStockMappings = result.Plates.Select((value, index) =>
                     new NestPlateStockMapping(index, value.Stock.Id)).ToArray(),
                 Nest = nest,
@@ -209,11 +213,13 @@ public static class NestRunner
                     plate.Quantity,
                     plate.PartSpacing,
                     plate.EdgeSpacing,
-                    plate.Quadrant
+                    plate.Quadrant,
+                    plate.Cost
                 )
             );
         }
 
+        NestJobValidator.ValidateStockCosts(stock);
         return stock;
     }
 

OpenNest.Core/CNC/CuttingPlanning/LeadMaterialSnapshot.cs

@@ -4,6 +4,7 @@ using System.Linq;
 using System.Threading;
 using OpenNest.Diagnostics;
 using OpenNest.Geometry;
+using OpenNest.Math;
 
 namespace OpenNest.CNC.CuttingPlanning;
 
@@ -46,7 +47,7 @@ public sealed class LeadMaterialSnapshot
                 if (chain.Count > 0 && chain[^1].End.DistanceTo(curve.Start) > PostVerificationGeometry.Epsilon)
                     throw new ArgumentException("Material contour is discontinuous.");
                 chain.Add(curve);
-                if (PostVerificationGeometry.Closed(chain))
+                if (NominalContourClosure.IsClosed(chain[0].Start, chain[^1].End))
                     Finish();
             }
             Finish();
@@ -66,11 +67,23 @@ public sealed class LeadMaterialSnapshot
                             var b = rings[s][j];
                             var contacts = a.Contacts(b, out var overlap);
                             var adjacent = r == s && (j == i + 1 || (i == 0 && j == rings[r].Length - 1));
+                            var arcJoint = adjacent && a.IsFiniteArc && b.IsFiniteArc
+                                && (a.End.DistanceTo(b.Start) <= Tolerance.Epsilon
+                                    || a.Start.DistanceTo(b.End) <= Tolerance.Epsilon);
+                            // Native arc queries pad angles by 1e-5 radians, admitting
+                            // intersections on an extension (distance grows with radius).
+                            // At a shared arc joint require both actual finite spans;
+                            // overlap and genuine second intersections still refuse.
+                            if (arcJoint)
+                                contacts = contacts.Where(p => !a.IsOutsideArcSpan(p) && !b.IsOutsideArcSpan(p)).ToArray();
+                            // Native contacts at rounded arc/line joints can drift from the
+                            // authored endpoint. Use the shared geometry tolerance only to
+                            // recognize that joint; overlaps and other contacts still refuse.
                             if (overlap || contacts.Any(p => !adjacent
-                                || !(p.DistanceTo(a.End) <= PostVerificationGeometry.Epsilon
+                                || !(p.DistanceTo(a.End) <= Tolerance.Epsilon
-                                    && p.DistanceTo(b.Start) <= PostVerificationGeometry.Epsilon)
+                                    && p.DistanceTo(b.Start) <= Tolerance.Epsilon)
-                                && !(p.DistanceTo(a.Start) <= PostVerificationGeometry.Epsilon
+                                && !(p.DistanceTo(a.Start) <= Tolerance.Epsilon
-                                    && p.DistanceTo(b.End) <= PostVerificationGeometry.Epsilon)))
+                                    && p.DistanceTo(b.End) <= Tolerance.Epsilon)))
                                 throw new ArgumentException($"Material boundaries overlap, touch or self-intersect ({r}:{i}, {s}:{j}, overlap={overlap}).");
                         }
             var outer = -1;
@@ -97,8 +110,13 @@ public sealed class LeadMaterialSnapshot
             {
                 if (chain.Count == 0)
                     return;
-                if (!PostVerificationGeometry.Closed(chain))
+                if (!NominalContourClosure.IsClosed(chain[0].Start, chain[^1].End))
-                    throw new ArgumentException("Nominal material contour is open; tab gaps cannot be filled implicitly.");
+                {
+                    var gap = chain[0].Start.DistanceTo(chain[^1].End);
+                    throw new ArgumentException(FormattableString.Invariant(
+                        $"Nominal material contour {rings.Count + 1} is open: endpoint gap {gap:G6} model units exceeds closure tolerance {NominalContourClosure.Tolerance:G6}.")
+                        + " Review the source contour in the drawing editor; gaps cannot be filled implicitly.");
+                }
                 rings.Add(chain.ToArray());
                 chain.Clear();
             }

OpenNest.Core/CNC/CuttingPlanning/LeadPathValidator.cs

@@ -113,7 +113,8 @@ public static class LeadPathValidator
                     return material.ContainsMaterial(move.Curve.Midpoint, token) ? "interior" : null;
                 }
             }
-            // Missing leads are the ReleasedContourState check's responsibility.
+            // No lead motion is valid for direct contour piercing. The caller still
+            // checks rapid travel and contour accounting for the complete program.
             return new(true, true, null);
         }
         catch (Exception ex) when (ex is ArgumentException or NotSupportedException)

OpenNest.Core/CNC/CuttingPlanning/NominalContourClosure.cs

@@ -0,0 +1,20 @@
+using OpenNest.Geometry;
+
+namespace OpenNest.CNC.CuttingPlanning;
+
+/// <summary>Closure of source contours during planner material capture and preparation.</summary>
+internal static class NominalContourClosure
+{
+    internal const double Tolerance = 0.000001;
+
+    internal static bool IsClosed(Vector start, Vector end)
+    {
+        // Subtracting translated/rotated coordinates can put an exact boundary gap
+        // a few floating-point ulps above the limit. Bound that allowance to 1e-12.
+        var scale = System.Math.Max(1, System.Math.Max(
+            System.Math.Max(System.Math.Abs(start.X), System.Math.Abs(start.Y)),
+            System.Math.Max(System.Math.Abs(end.X), System.Math.Abs(end.Y))));
+        var roundoff = System.Math.Min(1e-12, 4 * 2.2204460492503131e-16 * scale);
+        return start.DistanceTo(end) <= Tolerance + roundoff;
+    }
+}

OpenNest.Core/CNC/CuttingPlanning/PreparedContours.cs

@@ -74,7 +74,7 @@ public sealed class PreparedContours
             if (current.Entities.Count > 0 && End(current.Entities[^1]).DistanceTo(Start(entity)) > PostVerificationGeometry.Epsilon)
                 throw new ArgumentException("Discontinuous native contour.");
             current.Entities.Add(entity);
-            if (Start(current.Entities[0]).DistanceTo(End(entity)) <= PostVerificationGeometry.Epsilon)
+            if (NominalContourClosure.IsClosed(Start(current.Entities[0]), End(entity)))
                 FinishContour();
         }
         if (current.Entities.Count != 0 || contours.Count == 0)
@@ -254,12 +254,11 @@ public sealed class PreparedContours
                          .Where(p => p.Kind == AutomaticEntryKind.ConvexCorner))
             {
                 token.ThrowIfCancellationRequested();
-                var cornerPoint = End(shape.Entities[corner.EntityOrdinal]);
                 // Back INTO each incident edge from the corner: the edge ending at the
                 // corner retreats against its own travel, the edge starting at the corner
                 // advances along its own travel.
-                AddInset(corner.EntityOrdinal, cornerPoint, inward: false);
+                AddInset(corner.EntityOrdinal, inward: false);
-                AddInset((corner.EntityOrdinal + 1) % count, cornerPoint, inward: true);
+                AddInset((corner.EntityOrdinal + 1) % count, inward: true);
             }
         }
 
@@ -276,7 +275,7 @@ public sealed class PreparedContours
         token.ThrowIfCancellationRequested();
         return fallbacks;
 
-        void AddInset(int entityOrdinal, Vector corner, bool inward)
+        void AddInset(int entityOrdinal, bool inward)
         {
             // `inward` selects along the edge's own travel from its start; without it the
             // point retreats against travel. Both ways move BACK INTO the edge from the
@@ -285,7 +284,9 @@ public sealed class PreparedContours
                 return;
             var direction = (line.EndPoint - line.StartPoint).Normalize();
             var offset = direction * (2 * lead);
-            var point = inward ? corner + offset : corner - offset;
+            // Adjacent native endpoints may differ within contour-continuity tolerance.
+            // Anchor to the selected edge itself, never the preceding edge's vertex.
+            var point = inward ? line.StartPoint + offset : line.EndPoint - offset;
             // Strictly inside the edge by projection parameter (distance alone loses the
             // sign when a short edge is overshoot): never the corner, never the far
             // endpoint (where a reflex vertex might sit). Short edges omit the point.

OpenNest.Core/CNC/CuttingPlanning/ReleasedContourState.cs

@@ -11,10 +11,20 @@ namespace OpenNest.CNC.CuttingPlanning;
 public sealed class ReleasedContourState
 {
     private readonly List<Obstacle> obstacles = new();
+    private readonly bool reportMissingLeadIns;
+
+    public ReleasedContourState() : this(true) { }
+
+    /// <param name="reportMissingLeadIns">Keep pre-post warnings by default. Planning
+    /// may pierce directly on a contour and checks travel without requiring a lead.</param>
+    public ReleasedContourState(bool reportMissingLeadIns)
+    {
+        this.reportMissingLeadIns = reportMissingLeadIns;
+    }
 
     public ReleasedContourState Copy()
     {
-        var copy = new ReleasedContourState();
+        var copy = new ReleasedContourState(reportMissingLeadIns);
         copy.obstacles.AddRange(obstacles);
         return copy;
     }
@@ -68,7 +78,13 @@ public sealed class ReleasedContourState
                     if (PostVerificationGeometry.Crosses(start, move.End, obstacle.Curves, token))
                         findings.Add(new(PostVerificationKind.RapidCrossing, plate, part, obstacle.Part,
                             $"Direct XY rapid crosses or touches completed untabbed contour {obstacle.Contour} " +
-                            $"of part {obstacle.Part}."));
+                            $"of part {obstacle.Part}.")
+                        {
+                            Location = (start + move.End) * 0.5,
+                            RapidStart = start,
+                            RapidEnd = move.End,
+                            ContactPoints = PostVerificationGeometry.ContactPoints(start, move.End, obstacle.Curves, token)
+                        });
                 }
             }
             else if (move.Layer == LayerType.Leadin)
@@ -92,9 +108,10 @@ public sealed class ReleasedContourState
                 if (contour.Count == 0)
                 {
                     contourNumber++;
-                    if (!cutoff && !hasLead)
+                    if (reportMissingLeadIns && !cutoff && !hasLead)
                         findings.Add(new(PostVerificationKind.MissingLeadIn, plate, part, null,
-                            $"Cutting contour {contourNumber} has no nonzero placed lead-in motion."));
+                            $"Cutting contour {contourNumber} has no nonzero placed lead-in motion.")
+                        { Location = move.Curve.Start });
                     hasLead = false;
                     // A rapid can pause/reposition without leaving any material gap.
                     // Retain already-cut fragments, but do not turn them into obstacles

OpenNest.Core/Diagnostics/PostVerificationAnalyzer.cs

@@ -113,7 +113,8 @@ public static class PostVerificationAnalyzer
                 PlateOverlapAnalyzer.Capture(materialParts, cancellationToken), cancellationToken);
             foreach (var pair in overlap.Pairs)
                 findings.Add(new(PostVerificationKind.Overlap, plateNumber, indices[pair.PartAId],
-                    indices[pair.PartBId], "Clean drawing material overlaps (holes subtracted)."));
+                    indices[pair.PartBId], "Clean drawing material overlaps (holes subtracted).")
+                { Location = pair.Centroid, Overlap = pair });
             foreach (var issue in overlap.Issues)
                 findings.Add(new(PostVerificationKind.Incomplete, plateNumber, indices[issue.PartAId],
                     issue.PartBId is { } other ? indices[other] : null, "Overlap check: " + issue.Message));

OpenNest.Core/Diagnostics/PostVerificationGeometry.cs

@@ -89,6 +89,30 @@ internal static class PostVerificationGeometry
         return inside;
     }
 
+    internal static IReadOnlyList<Vector> ContactPoints(Vector start, Vector end,
+        IReadOnlyList<Curve> curves, CancellationToken token)
+    {
+        var length = start.DistanceTo(end);
+        if (length <= Epsilon)
+            return Array.Empty<Vector>();
+        var direction = (end - start) * (1 / length);
+        var distances = new List<double>();
+        foreach (var curve in curves)
+        {
+            token.ThrowIfCancellationRequested();
+            curve.ContactAfterStart(start, direction, length, distances);
+        }
+        distances.Sort();
+        var points = new List<Vector>();
+        foreach (var distance in distances)
+        {
+            var point = start + direction * distance;
+            if (points.Count == 0 || points[^1].DistanceTo(point) > Epsilon)
+                points.Add(point);
+        }
+        return points.AsReadOnly();
+    }
+
     private static double Dot(Vector a, Vector b) => a.X * b.X + a.Y * b.Y;
     private static double Cross(Vector a, Vector b) => a.X * b.Y - a.Y * b.X;
     private static double Normalize(double angle)
@@ -106,8 +130,13 @@ internal static class PostVerificationGeometry
             Center = center;
             Radius = radius;
             Sweep = sweep;
+            nativeEntity = new Lazy<Entity>(ToEntity);
         }
 
+        // Never expose this mutable native wrapper; its geometry is read-only after creation.
+        // Lazy preserves the old conversion point for unsupported curves and is safe for concurrent checks.
+        private readonly Lazy<Entity> nativeEntity;
+
         internal Vector Start { get; }
         internal Vector End { get; }
         private Vector? Center { get; }
@@ -170,12 +199,21 @@ internal static class PostVerificationGeometry
                 : Start + (End - Start) * (distance / Length);
         }
 
-        internal bool Contains(Vector point) => ToEntity().ClosestPointTo(point).DistanceTo(point) <= Epsilon;
+        internal bool Contains(Vector point) => nativeEntity.Value.ClosestPointTo(point).DistanceTo(point) <= Epsilon;
+
+        /// <summary>
+        /// Filters supporting-circle contacts against the actual finite arc span. The
+        /// native angular padding is larger and must not turn an arc extension into a
+        /// self-intersection at an adjacent nominal joint. This is not a radial test.
+        /// </summary>
+        internal bool IsOutsideArcSpan(Vector point) => Center.HasValue && !OnArc(point);
+
+        internal bool IsFiniteArc => Center.HasValue && System.Math.Abs(Sweep) < TwoPi;
 
         internal IReadOnlyList<Vector> Contacts(Curve other, out bool overlap)
         {
-            var entity = ToEntity();
+            var entity = nativeEntity.Value;
-            var candidate = other.ToEntity();
+            var candidate = other.nativeEntity.Value;
             // Native arc filters discard NaN supporting-circle intersections. Inspect
             // both unfiltered queries first: roundoff can differ by operand direction.
             // Coincident supports have separate overlap handling below.
@@ -281,7 +319,8 @@ internal static class PostVerificationGeometry
         // The largest distance from the centre that ContactAfterStart can count as contact.
         private double ContactReach => System.Math.Sqrt(Radius * Radius + ContactSlack);
 
-        internal bool ContactAfterStart(Vector origin, Vector direction, double length)
+        internal bool ContactAfterStart(Vector origin, Vector direction, double length,
+            List<double> contacts = null)
         {
             if (Center is { } center)
             {
@@ -294,10 +333,13 @@ internal static class PostVerificationGeometry
                 if (square < -ContactSlack)
                     return false;
                 var offset = System.Math.Sqrt(System.Math.Max(0, square));
-                return Hit(projection - offset) || Hit(projection + offset);
+                return contacts == null
+                    ? Hit(projection - offset) || Hit(projection + offset)
+                    : Hit(projection - offset) | Hit(projection + offset);
 
                 bool Hit(double distance) => distance > Epsilon && distance <= length + Epsilon
-                    && OnArc(origin + direction * System.Math.Clamp(distance, 0, length));
+                    && OnArc(origin + direction * System.Math.Clamp(distance, 0, length))
+                    && Record(distance);
             }
             var edge = End - Start;
             var relativeStart = Start - origin;
@@ -310,13 +352,20 @@ internal static class PostVerificationGeometry
                 var b = Dot(End - origin, direction);
                 var low = System.Math.Max(0, System.Math.Min(a, b));
                 var high = System.Math.Min(length, System.Math.Max(a, b));
-                return high > Epsilon && low <= high + Epsilon;
+                return high > Epsilon && low <= high + Epsilon && Record(low) && Record(high);
             }
             var distanceAlongRapid = Cross(relativeStart, edge) / denominator;
             var fractionAlongEdge = Cross(relativeStart, direction) / denominator;
             return distanceAlongRapid > Epsilon && distanceAlongRapid <= length + Epsilon
                 && fractionAlongEdge >= -Epsilon / System.Math.Max(Length, Epsilon)
-                && fractionAlongEdge <= 1 + Epsilon / System.Math.Max(Length, Epsilon);
+                && fractionAlongEdge <= 1 + Epsilon / System.Math.Max(Length, Epsilon)
+                && Record(distanceAlongRapid);
+
+            bool Record(double distance)
+            {
+                contacts?.Add(System.Math.Clamp(distance, 0, length));
+                return true;
+            }
         }
 
         internal bool CrossesRay(Vector point)

OpenNest.Core/Diagnostics/PostVerificationReport.cs

@@ -2,6 +2,7 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
+using OpenNest.Geometry;
 
 namespace OpenNest.Diagnostics;
 
@@ -15,7 +16,15 @@ public enum PostVerificationKind
 
 /// <summary>Plate and part numbers are one-based; plate zero denotes a whole-post limitation.</summary>
 public sealed record PostVerificationFinding(PostVerificationKind Kind, int PlateNumber,
-    int? PartNumber, int? OtherPartNumber, string Message);
+    int? PartNumber, int? OtherPartNumber, string Message)
+{
+    public Vector? Location { get; init; }
+    public Vector? RapidStart { get; init; }
+    public Vector? RapidEnd { get; init; }
+    /// <summary>Rapid boundary contacts in travel order; collinear contact spans use their endpoints.</summary>
+    public IReadOnlyList<Vector> ContactPoints { get; init; } = Array.Empty<Vector>();
+    public PlateOverlapPair Overlap { get; init; }
+}
 
 /// <summary>Owned, immutable findings. Consent is evaluated afresh, never stored.</summary>
 public sealed class PostVerificationReport
@@ -29,10 +38,12 @@ public sealed class PostVerificationReport
     public bool HasWarnings => Findings.Count != 0;
     public bool CanPost(bool risksAcknowledged) => !HasWarnings || risksAcknowledged;
 
-    public string ToDisplayText()
+    public string ToDisplayText() => ToDisplayText("Pre-post verification");
+
+    public string ToDisplayText(string title)
     {
         var text = new StringBuilder();
-        text.AppendLine("Pre-post verification");
+        text.AppendLine(title);
         var incomplete = Findings.Any(finding => finding.Kind == PostVerificationKind.Incomplete);
         Summary(PostVerificationKind.Overlap, "Overlap");
         Summary(PostVerificationKind.MissingLeadIn, "Missing lead-ins");

OpenNest.Core/Drawing.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Drawing;
 using System.Linq;
@@ -32,13 +32,18 @@ namespace OpenNest
             Color.FromArgb(215, 130, 130), // Light Coral
         };
 
-        public static Color GetNextColor()
+        public static bool UseGoldenAngleColors { get; set; }
+
+        public static Color GetPartColor(int index)
         {
-            var color = PartColors[nextColorIndex % PartColors.Length];
+            ArgumentOutOfRangeException.ThrowIfNegative(index);
-            nextColorIndex++;
+            return UseGoldenAngleColors
-            return color;
+                ? PartColorPalette.GoldenAngle(index)
+                : PartColors[index % PartColors.Length];
         }
 
+        public static Color GetNextColor() => GetPartColor(unchecked(nextColorIndex++) & int.MaxValue);
+
         public Drawing()
             : this(string.Empty, new Program()) { }
 

OpenNest.Core/PartColorPalette.cs

@@ -0,0 +1,57 @@
+using System;
+using System.Drawing;
+
+namespace OpenNest
+{
+    /// <summary>
+    /// Drawing colors: golden-angle hue walk (skipping the etch-green band)
+    /// cycled through eight saturation/lightness tiers for wide separation.
+    /// </summary>
+    public static class PartColorPalette
+    {
+        // (lightness, saturation) tiers cycled on an irrational stride so any
+        // window of neighboring parts spans clearly different tones.
+        private static readonly (double Lightness, double Saturation)[] Tiers =
+        {
+            (0.52, 0.68), (0.64, 0.46), (0.75, 0.54), (0.61, 0.87),
+            (0.79, 0.97), (0.43, 0.82), (0.65, 0.76), (0.48, 0.97),
+        };
+
+        // Plastic-number stride: tier(i) never falls into a short repeating phase with the hue walk.
+        private const double TierStride = 0.7548776662466927;
+
+        // Hues land in [0,95) + [170,295) mapped onto the golden-angle cycle,
+        // keeping fills out of the bright-green etch band.
+        private const double HueSpan = 295.0;
+        private const double BandStart = 95.0;
+        private const double BandWidth = 75.0;
+
+        public static Color GoldenAngle(int index)
+        {
+            ArgumentOutOfRangeException.ThrowIfNegative(index);
+            var hue = index * 137.508 % HueSpan;
+            if (hue >= BandStart)
+                hue += BandWidth;
+            var (lightness, saturation) = Tiers[
+                unchecked((int)(Tiers.Length * (index * TierStride % 1.0)) % Tiers.Length)];
+
+            var q = lightness < 0.5
+                ? lightness * (1 + saturation)
+                : lightness + saturation - lightness * saturation;
+            var p = 2 * lightness - q;
+
+            int Channel(double t)
+            {
+                t = (t % 1 + 1) % 1;
+                var value = t < 1 / 6.0 ? p + (q - p) * 6 * t
+                    : t < 0.5 ? q
+                    : t < 2 / 3.0 ? p + (q - p) * (2 / 3.0 - t) * 6
+                    : p;
+                return (int)System.Math.Round(value * 255);
+            }
+
+            var h = hue / 360.0;
+            return Color.FromArgb(Channel(h + 1 / 3.0), Channel(h), Channel(h - 1 / 3.0));
+        }
+    }
+}

OpenNest.Core/Sequencing/ManualPartSequencing.cs

@@ -0,0 +1,29 @@
+using System;
+using System.Linq;
+
+namespace OpenNest.Sequencing
+{
+    /// <summary>Moves one existing part to a one-based cutting sequence position.</summary>
+    public static class ManualPartSequencing
+    {
+        public static bool Move(Plate plate, Part part, int sequenceNumber)
+        {
+            ArgumentNullException.ThrowIfNull(plate);
+            ArgumentNullException.ThrowIfNull(part);
+            var order = plate.Parts.ToList();
+            if (sequenceNumber < 1 || sequenceNumber > order.Count)
+                return false;
+
+            var oldIndex = order.FindIndex(p => ReferenceEquals(p, part));
+            if (oldIndex < 0)
+                return false;
+            if (oldIndex == sequenceNumber - 1)
+                return true;
+
+            order.RemoveAt(oldIndex);
+            order.Insert(sequenceNumber - 1, part);
+            plate.Parts.Reorder(order);
+            return true;
+        }
+    }
+}

OpenNest.Data/NestBrowseSession.cs

@@ -15,7 +15,8 @@ public sealed class NestBrowseSession : IDisposable
     private int _generation;
     private bool _disposed;
 
-    public NestBrowseSession(INestRepository repository, int pageSize = NestQuery.DefaultLimit)
+    public NestBrowseSession(INestRepository repository, int pageSize = NestQuery.DefaultLimit,
+        NestSortField sort = NestSortField.SavedAt, bool descending = true)
     {
         ArgumentNullException.ThrowIfNull(repository);
         if (pageSize < 1 || pageSize > NestQuery.MaxLimit)
@@ -23,6 +24,8 @@ public sealed class NestBrowseSession : IDisposable
 
         _repository = repository;
         PageSize = pageSize;
+        Sort = Enum.IsDefined(sort) ? sort : NestSortField.SavedAt;
+        Descending = descending;
     }
 
     public int PageSize { get; }

OpenNest.Data/NestDetailsSession.cs

@@ -4,11 +4,20 @@ namespace OpenNest.Data;
 /// Loads the details of the nest highlighted in the Database-mode nest browser. Moving
 /// the highlight starts a new load and cancels the previous one; a superseded load's
 /// result or failure is discarded, so details never belong to a nest that is no longer
-/// highlighted. Call from one thread (the UI thread).
+/// highlighted. Also holds a small LRU cache of recently shown or <see cref="Prefetch"/>ed
+/// nests, so browsing back onto one, or onto one a caller warmed ahead of time, resolves
+/// without a server round trip. Call from one thread (the UI thread).
 /// </summary>
 public sealed class NestDetailsSession : IDisposable
 {
+    // Bounds memory from cached plate/drawing geometry; generous enough for a caller's
+    // prefetch window plus some scrollback before the oldest entries are evicted.
+    private const int CacheCapacity = 25;
+
     private readonly Func<Guid, CancellationToken, Task<NestDetails>> _load;
+    private readonly Dictionary<Guid, NestDetails> _cache = new();
+    private readonly List<Guid> _cacheOrder = new();
+    private readonly Dictionary<Guid, CancellationTokenSource> _prefetches = new();
     private CancellationTokenSource? _pending;
     private int _generation;
     private bool _disposed;
@@ -49,7 +58,18 @@ public sealed class NestDetailsSession : IDisposable
 
         try
         {
-            var details = await _load(id, cancellation.Token);
+            NestDetails details;
+            if (_cache.TryGetValue(id, out var cached))
+            {
+                Touch(id);
+                details = cached;
+            }
+            else
+            {
+                details = await _load(id, cancellation.Token);
+                Remember(id, details);
+            }
+
             if (generation != _generation)
                 return false;
 
@@ -70,7 +90,63 @@ public sealed class NestDetailsSession : IDisposable
         }
     }
 
-    /// <summary>Forgets the current details and discards any load in flight (no nest highlighted).</summary>
+    /// <summary>
+    /// Starts loading one nest's details in the background so a later <see cref="LoadAsync"/>
+    /// for it resolves from the cache instead of the server. Skipped when the nest is already
+    /// cached, already prefetching, or is the loaded/loading nest. Failures are swallowed here;
+    /// an on-demand load surfaces the error if the nest is actually selected later.
+    /// </summary>
+    public void Prefetch(Guid id)
+    {
+        ObjectDisposedException.ThrowIf(_disposed, this);
+        if (id == NestId || _cache.ContainsKey(id) || _prefetches.ContainsKey(id))
+            return;
+
+        var cancellation = new CancellationTokenSource();
+        _prefetches[id] = cancellation;
+        _ = PrefetchCoreAsync(id, cancellation);
+    }
+
+    private async Task PrefetchCoreAsync(Guid id, CancellationTokenSource cancellation)
+    {
+        try
+        {
+            var details = await _load(id, cancellation.Token);
+            if (!cancellation.IsCancellationRequested)
+                Remember(id, details);
+        }
+        catch
+        {
+            // Silent: this prefetch only mattered if the nest is later selected, and
+            // LoadAsync's own on-demand fetch will surface the error then.
+        }
+        finally
+        {
+            if (ReferenceEquals(_prefetches.GetValueOrDefault(id), cancellation))
+                _prefetches.Remove(id);
+            cancellation.Dispose();
+        }
+    }
+
+    private void Remember(Guid id, NestDetails details)
+    {
+        _cache[id] = details;
+        Touch(id);
+        while (_cacheOrder.Count > CacheCapacity)
+        {
+            var oldest = _cacheOrder[0];
+            _cacheOrder.RemoveAt(0);
+            _cache.Remove(oldest);
+        }
+    }
+
+    private void Touch(Guid id)
+    {
+        _cacheOrder.Remove(id);
+        _cacheOrder.Add(id);
+    }
+
+    /// <summary>Forgets the current details and discards any load or prefetch in flight.</summary>
     public void Clear()
     {
         if (_disposed)
@@ -83,6 +159,8 @@ public sealed class NestDetailsSession : IDisposable
         Details = null;
         IsLoading = false;
         pending?.Cancel();
+        foreach (var prefetch in _prefetches.Values)
+            prefetch.Cancel();
     }
 
     private CancellationTokenSource Supersede()

OpenNest.Data/NestStorageSettings.cs

@@ -32,6 +32,18 @@ public sealed class NestStorageSettings
     public bool IsDatabaseMode =>
         Mode == NestStorageMode.Database && !string.IsNullOrWhiteSpace(ServerUrl);
 
+    /// <summary>Validate and normalize a nest server base URL without changing storage mode.</summary>
+    public static bool TryNormalizeServerUrl(string? url, out string normalized)
+    {
+        normalized = NormalizeUrl(url);
+        if (Uri.TryCreate(normalized, UriKind.Absolute, out var uri)
+            && (uri.Scheme == Uri.UriSchemeHttp || uri.Scheme == Uri.UriSchemeHttps))
+            return true;
+
+        normalized = "";
+        return false;
+    }
+
     /// <summary>%APPDATA%\OpenNest\storage.json.</summary>
     public static string DefaultPath => Path.Combine(
         Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData),

OpenNest.Engine.Tests/Jobs/Cutouts/CutoutNfpProposalTests.cs

@@ -0,0 +1,154 @@
+using OpenNest.Engine.Jobs;
+using OpenNest.Engine.Jobs.Cutouts;
+using OpenNest.Engine.Tests.NestingEngines;
+using TestShapes = OpenNest.Engine.Tests.NestingEngines.Shapes;
+
+namespace OpenNest.Engine.Tests.Jobs.Cutouts;
+
+public class CutoutNfpProposalTests
+{
+    private const double Spacing = 0.25;
+
+    [Fact]
+    public void LargeInsertFitsRoundCutoutAndRemainsValidAfterFrameRotation()
+    {
+        var frame = JobBuilder.Part("frame", TestShapes.Ring(20, 10), 1, RotationPolicy.Fixed(System.Math.PI / 2));
+        var insert = JobBuilder.Rectangle("insert", 6, 6, 1, RotationPolicy.Fixed(0));
+        var pose = CutoutNfpProposal.Find(frame, 0, insert, Spacing);
+        Assert.NotNull(pose);
+        Assert.Equal(insert.Id, pose.PartId);
+        Assert.Equal(0, pose.InstanceIndex);
+        Assert.True(insert.Rotation.Allows(pose.Rotation));
+        AssertSquareInRoundHole(pose, 6, Spacing);
+
+        var localFrame = new NestJobPlacement(frame.Id, 0, 0, 0, 0);
+        Assert.True(NestLayoutCheck.Clears(JobPartGeometry.Read(frame.Geometry), localFrame,
+            JobPartGeometry.Read(insert.Geometry), pose, Spacing));
+        var framePose = new NestJobPlacement(frame.Id, 0, 11, 11, System.Math.PI / 2);
+        var movedInsert = pose with
+        {
+            X = framePose.X - pose.Y,
+            Y = framePose.Y + pose.X,
+            Rotation = pose.Rotation + framePose.Rotation,
+        };
+        // This insert is fixed at zero for the local proposal; the rotated variant needs
+        // a correspondingly legal global policy before it can be handed to a job.
+        var rotatedInsert = JobBuilder.Rectangle("insert", 6, 6, 1, RotationPolicy.Fixed(System.Math.PI / 2));
+        Assert.True(NestLayoutCheck.Clears(JobPartGeometry.Read(frame.Geometry), framePose,
+            JobPartGeometry.Read(insert.Geometry), movedInsert, Spacing));
+        AssertSquareInRoundHole(movedInsert, 6, Spacing, framePose.X, framePose.Y);
+        var stock = JobBuilder.Stock("sheet", 22, 22, Spacing);
+        var job = JobBuilder.Job(new[] { frame, rotatedInsert }, new[] { stock });
+        var result = new NestJobResult(NestJobStatus.Complete, NestJobStopReason.Completed,
+            new[] { new NestJobPlateResult(0, stock, new[] { framePose, movedInsert }) },
+            new[] { new PartFulfillment(frame.Id, 1, 1, 0), new PartFulfillment(insert.Id, 1, 1, 0) },
+            new[] { new StockUsage(stock.Id, 1, null) });
+        LayoutAssert.Valid(job, result);
+    }
+
+    [Fact]
+    public void LargeInsertFitsSquareCutoutWithoutUsingFillLattice()
+    {
+        var program = TestShapes.Rectangle(20, 20);
+        program.MoveTo(5, 5);
+        program.LineTo(5, 15);
+        program.LineTo(15, 15);
+        program.LineTo(15, 5);
+        program.LineTo(5, 5);
+        var frame = JobBuilder.Part("square-frame", program, 1);
+        var insert = JobBuilder.Rectangle("large", 9, 9, 1, RotationPolicy.Fixed(0));
+        var pose = CutoutNfpProposal.Find(frame, 0, insert, Spacing);
+        Assert.NotNull(pose);
+        Assert.All(new[] { (0.0, 0.0), (9.0, 0.0), (9.0, 9.0), (0.0, 9.0) }, corner =>
+        {
+            Assert.InRange(pose.X + corner.Item1, 5 + Spacing, 15 - Spacing);
+            Assert.InRange(pose.Y + corner.Item2, 5 + Spacing, 15 - Spacing);
+        });
+        Assert.True(NestLayoutCheck.Clears(JobPartGeometry.Read(frame.Geometry),
+            new NestJobPlacement(frame.Id, 0, 0, 0, 0), JobPartGeometry.Read(insert.Geometry), pose, Spacing));
+        Assert.Null(CutoutNfpProposal.Find(frame, 0, JobBuilder.Rectangle("oversized", 9.6, 9.6, 1),
+            Spacing));
+    }
+
+    [Fact]
+    public void ObliqueFixedInsertRotationIsUsedInInnerFit()
+    {
+        var program = TestShapes.Rectangle(20, 20);
+        program.MoveTo(5, 5);
+        program.LineTo(5, 15);
+        program.LineTo(15, 15);
+        program.LineTo(15, 5);
+        program.LineTo(5, 5);
+        var frame = JobBuilder.Part("frame", program, 1);
+        var insert = JobBuilder.Rectangle("insert", 3, 2, 1, RotationPolicy.Fixed(System.Math.PI / 4));
+        var pose = CutoutNfpProposal.Find(frame, 0, insert, Spacing);
+        Assert.NotNull(pose);
+        Assert.True(insert.Rotation.Allows(pose.Rotation));
+        foreach (var (x, y) in new[] { (0.0, 0.0), (3.0, 0.0), (3.0, 2.0), (0.0, 2.0) })
+        {
+            var rx = pose.X + x * System.Math.Cos(pose.Rotation) - y * System.Math.Sin(pose.Rotation);
+            var ry = pose.Y + x * System.Math.Sin(pose.Rotation) + y * System.Math.Cos(pose.Rotation);
+            Assert.InRange(rx, 5 + Spacing, 15 - Spacing);
+            Assert.InRange(ry, 5 + Spacing, 15 - Spacing);
+        }
+    }
+
+    [Theory]
+    [InlineData(9.51)]
+    [InlineData(10.0)]
+    [InlineData(9.6)]
+    public void OversizedInsertIsNeverProposed(double side)
+    {
+        var frame = JobBuilder.Part("frame", TestShapes.Ring(20, 10), 1);
+        var insert = JobBuilder.Rectangle("insert", side, side, 1);
+        Assert.Null(CutoutNfpProposal.Find(frame, 0, insert, Spacing));
+    }
+
+    [Fact]
+    public void UnsupportedCoordinateScaleFailsClosed()
+    {
+        const double scale = 1e15;
+        var program = TestShapes.Polyline((-scale, -scale), (scale, -scale),
+            (scale, scale), (-scale, scale));
+        program.MoveTo(-scale / 2, -scale / 2);
+        program.LineTo(-scale / 2, scale / 2);
+        program.LineTo(scale / 2, scale / 2);
+        program.LineTo(scale / 2, -scale / 2);
+        program.LineTo(-scale / 2, -scale / 2);
+        Assert.Null(CutoutNfpProposal.Find(JobBuilder.Part("huge", program, 1), 0,
+            JobBuilder.Rectangle("insert", 6, 6, 1), Spacing));
+    }
+
+    [Fact]
+    public void ImpossibleHugeSpacingFailsBeforeAnyOffset()
+    {
+        var frame = JobBuilder.Part("frame", TestShapes.Ring(20, 10), 1);
+        var insert = JobBuilder.Rectangle("insert", 6, 6, 1);
+        Assert.Null(CutoutNfpProposal.Find(frame, 0, insert, 1e12));
+    }
+
+    private static void AssertSquareInRoundHole(NestJobPlacement pose, double side, double spacing,
+        double centerX = 0, double centerY = 0)
+    {
+        var sin = System.Math.Sin(pose.Rotation);
+        var cos = System.Math.Cos(pose.Rotation);
+        foreach (var (x, y) in new[] { (0.0, 0.0), (side, 0.0), (side, side), (0.0, side) })
+        {
+            var dx = pose.X + x * cos - y * sin - centerX;
+            var dy = pose.Y + x * sin + y * cos - centerY;
+            Assert.True(System.Math.Sqrt(dx * dx + dy * dy) <= 5 - spacing + 0.00001,
+                $"corner ({dx}, {dy}) does not clear the circular wall");
+        }
+    }
+
+    [Fact]
+    public void CancellationIsNotReportedAsNoFit()
+    {
+        var frame = JobBuilder.Part("frame", TestShapes.Ring(20, 10), 1);
+        var insert = JobBuilder.Rectangle("insert", 6, 6, 1);
+        using var cancelled = new CancellationTokenSource();
+        cancelled.Cancel();
+        Assert.Throws<OperationCanceledException>(() => CutoutNfpProposal.Find(frame, 0, insert, Spacing,
+            cancelled.Token));
+    }
+}

OpenNest.Engine.Tests/Jobs/Cutouts/CutoutPipelinePreviewTests.cs

@@ -0,0 +1,749 @@
+using OpenNest.CNC;
+using OpenNest.Engine.Jobs;
+using OpenNest.Engine.Jobs.Cutouts;
+using OpenNest.Geometry;
+using TestShapes = OpenNest.Engine.Tests.NestingEngines.Shapes;
+
+namespace OpenNest.Engine.Tests.Jobs.Cutouts;
+
+[CollectionDefinition("Cutout pipeline registry", DisableParallelization = true)]
+public sealed class CutoutPipelineRegistryCollection { }
+
+[Collection("Cutout pipeline registry")]
+public class CutoutPipelinePreviewTests
+{
+    private static NestPipelineRequest Request(string engine = "Irregular")
+    {
+        var frame = new Drawing("frame", TestShapes.Ring(20, 10));
+        var insert = new Drawing("insert", TestShapes.Rectangle(3, 3));
+        return new NestPipelineRequest(engine,
+            new[] { new NestItem { Drawing = frame, Quantity = 1 },
+                new NestItem { Drawing = insert, Quantity = 1 } },
+            new[] { new NestPlateStock("sheet", new Size(22, 22), 1, 0.25) });
+    }
+
+    [Theory]
+    [InlineData("Irregular")]
+    [InlineData("Default")]
+    public void RegisteredEngineExpandsOnlyPhysicalOriginalDrawings(string engine)
+    {
+        var request = Request(engine);
+        var result = NestPipeline.RunCutoutPreview(request);
+        Assert.True(result.IsValid, string.Join("; ", result.Violations));
+        Assert.True(result.CanKeep);
+        var plate = Assert.Single(result.Plates);
+        Assert.Equal(2, plate.Parts.Count);
+        Assert.Same(request.Items[0].Drawing, plate.Parts[0].BaseDrawing);
+        Assert.Same(request.Items[1].Drawing, plate.Parts[1].BaseDrawing);
+        Assert.Equal(new[] { "part-0", "part-1" }, result.Raw.Plates[0].Placements.Select(p => p.PartId));
+        Assert.All(result.Raw.Fulfillment, f => Assert.Equal((1, 1, 0), (f.Requested, f.Placed, f.Unplaced)));
+        Assert.Equal(0, request.Items[0].Drawing.Quantity.Nested);
+        Assert.Equal(0, request.Items[1].Drawing.Quantity.Nested);
+    }
+
+    private sealed class Stub(Func<NestJob, NestJobResult> solve) : INestingEngine
+    {
+        public NestJobResult Solve(NestJob job, IProgress<NestJobProgress>? progress = null,
+            CancellationToken token = default) => solve(job);
+    }
+
+    private static NestJobResult Result(NestJob job, params NestJobPlacement[] poses)
+    {
+        var placed = poses.GroupBy(p => p.PartId).ToDictionary(g => g.Key, g => g.Count());
+        var complete = job.Parts.All(p => placed.GetValueOrDefault(p.Id) == p.Quantity);
+        return new NestJobResult(complete ? NestJobStatus.Complete : NestJobStatus.Incomplete,
+            complete ? NestJobStopReason.Completed : NestJobStopReason.NoPlacementFound,
+            poses.Length == 0 ? Array.Empty<NestJobPlateResult>() :
+                new[] { new NestJobPlateResult(0, job.Plates[0], poses) },
+            job.Parts.Select(p => new PartFulfillment(p.Id, p.Quantity,
+                placed.GetValueOrDefault(p.Id), p.Quantity - placed.GetValueOrDefault(p.Id))),
+            new[] { new StockUsage(job.Plates[0].Id, poses.Length == 0 ? 0 : 1,
+                job.Plates[0].Quantity - (poses.Length == 0 ? 0 : 1)) });
+    }
+
+    [Fact]
+    public void SingleSolveReceivesOneProxyAndNoDuplicatedInsertDemand()
+    {
+        var called = 0;
+        var request = Request("stub");
+        var result = NestPipeline.RunCutoutPreview(new Stub(job =>
+        {
+            called++;
+            var proxy = Assert.Single(job.Parts);
+            Assert.StartsWith("__cutout-proxy-", proxy.Id);
+            Assert.True(proxy.Rotation.Allows(0));
+            Assert.False(proxy.Rotation.Allows(System.Math.PI / 2));
+            return Result(job, new NestJobPlacement(proxy.Id, 0, 11, 11, 0));
+        }), "stub", request);
+        Assert.Equal(1, called);
+        Assert.True(result.IsValid, string.Join("; ", result.Violations));
+        Assert.Equal(2, result.Plates.Single().Parts.Count);
+    }
+
+    [Fact]
+    public void IncompleteEngineDoesNotBindReservedInsertEvenWithInvalidConsent()
+    {
+        var request = Request("stub");
+        var result = NestPipeline.RunCutoutPreview(new Stub(job => Result(job)), "stub", request);
+        Assert.False(result.CanKeep);
+        Assert.Empty(result.Plates);
+        Assert.Contains(result.Violations, v => v.Contains("did not complete"));
+        Assert.All(result.Raw.Fulfillment, f => Assert.Equal((1, 0, 1),
+            (f.Requested, f.Placed, f.Unplaced)));
+        Assert.Equal(0, request.Items[1].Drawing.Quantity.Nested);
+        AssertCannotCommit(result, request);
+    }
+
+    [Fact]
+    public void ForgedFulfillmentOrDuplicateIndexDoesNotBindComposite()
+    {
+        var request = Request("stub");
+        var result = NestPipeline.RunCutoutPreview(new Stub(job =>
+        {
+            var id = job.Parts.Single(p => p.Id.StartsWith("__cutout-proxy-")).Id;
+            var pose = new NestJobPlacement(id, 1, 11, 11, 0);
+            return Result(job, pose);
+        }), "stub", request);
+        Assert.False(result.CanKeep);
+        Assert.Empty(result.Plates);
+        Assert.Contains(result.Violations, v => v.Contains("accounting"));
+    }
+
+    [Fact]
+    public void PartialBundleKeepsIndependentResidualByOriginalRequirement()
+    {
+        var request = Request("stub");
+        request.Items[1].Quantity = 2;
+        request = request with { Stock = new[] { new NestPlateStock("sheet", new Size(26, 26), 1, 0.25) } };
+        var result = NestPipeline.RunCutoutPreview(new Stub(job =>
+        {
+            var proxy = job.Parts.Single(p => p.Id.StartsWith("__cutout-proxy-"));
+            var residual = job.Parts.Single(p => p.Id == "part-1");
+            Assert.Equal(1, residual.Quantity);
+            return Result(job, new NestJobPlacement(proxy.Id, 0, 11, 11, 0),
+                new NestJobPlacement(residual.Id, 0, 22, 1, 0));
+        }), "stub", request);
+        Assert.True(result.IsValid, string.Join("; ", result.Violations));
+        Assert.Equal(new[] { "part-0", "part-1", "part-1" },
+            result.Raw.Plates.Single().Placements.Select(p => p.PartId));
+        Assert.Equal(new[] { 0, 1 }, result.Raw.Plates.Single().Placements
+            .Where(p => p.PartId == "part-1").Select(p => p.InstanceIndex));
+        Assert.All(result.Plates.Single().Parts.Where(p => p.BaseDrawing == request.Items[1].Drawing),
+            p => Assert.Same(request.Items[1].Drawing, p.BaseDrawing));
+    }
+
+    [Fact]
+    public void UntrustedStockOverdrawOrRotationCannotBindAComposite()
+    {
+        var request = Request("stub");
+        var result = NestPipeline.RunCutoutPreview(new Stub(job =>
+        {
+            var proxy = job.Parts.Single(p => p.Id.StartsWith("__cutout-proxy-"));
+            return Result(job, new NestJobPlacement(proxy.Id, 0, 11, 11,
+                System.Math.PI / 2));
+        }), "stub", request);
+        Assert.False(result.CanKeep);
+        Assert.Empty(result.Plates);
+        Assert.Contains(result.Violations, v => v.Contains("rotation constraint"));
+
+        var overdraw = NestPipeline.RunCutoutPreview(new Stub(job => new NestJobResult(
+            NestJobStatus.Complete, NestJobStopReason.Completed,
+            new[] { new NestJobPlateResult(0, job.Plates[0], new[] {
+                    new NestJobPlacement(job.Parts[0].Id, 0, 11, 11, 0) }),
+                new NestJobPlateResult(1, job.Plates[0], new[] {
+                    new NestJobPlacement(job.Parts[0].Id, 1, 11, 11, 0) }) },
+            Array.Empty<PartFulfillment>(), Array.Empty<StockUsage>())), "stub", request);
+        Assert.False(overdraw.CanKeep);
+        Assert.Empty(overdraw.Plates);
+        Assert.Contains(overdraw.Violations, v => v.Contains("only 1 are available"));
+    }
+
+    [Fact]
+    public void CancellationBeforePreparationDoesNotCallEngine()
+    {
+        using var cts = new CancellationTokenSource();
+        cts.Cancel();
+        var engine = new Stub(_ => throw new Exception("Must not call Solve"));
+        Assert.Throws<OperationCanceledException>(() =>
+            NestPipeline.RunCutoutPreview(engine, "stub", Request("stub"), token: cts.Token));
+    }
+
+    [Fact]
+    public void EnvelopeValidResidualInsideReservedHoleFailsAfterPhysicalExpansion()
+    {
+        var request = Request("stub");
+        request.Items[1].Quantity = 2;
+        var result = NestPipeline.RunCutoutPreview(new Stub(job =>
+        {
+            var proxy = job.Parts.Single(p => p.Id.StartsWith("__cutout-proxy-"));
+            return Result(job, new NestJobPlacement(proxy.Id, 0, 11, 11, 0),
+                new NestJobPlacement("part-1", 0, 11, 11, 0));
+        }), "stub", request);
+        Assert.False(result.CanKeep);
+        Assert.Empty(result.Plates);
+        Assert.Contains(result.Violations, v => v.Contains("required spacing"));
+        AssertCannotCommit(result, request);
+    }
+
+    private static void AssertCannotCommit(NestPipelineResult result, NestPipelineRequest request)
+    {
+        var nest = new Nest();
+        foreach (var item in request.Items)
+            nest.Drawings.Add(item.Drawing);
+        var empty = nest.CreatePlate();
+        using var manager = new PlateManager(nest);
+        Assert.Throws<InvalidOperationException>(() =>
+            NestPipelineCommit.ApplyToEmptyPlates(result, manager, allowInvalid: true));
+        Assert.Same(empty, Assert.Single(nest.Plates));
+        Assert.Empty(empty.Parts);
+        Assert.All(request.Items, item => Assert.Equal(0, item.Drawing.Quantity.Nested));
+    }
+
+    private sealed class CollectProgress : IProgress<NestJobProgress>
+    {
+        public List<NestJobProgress> Events { get; } = new();
+        public void Report(NestJobProgress value) => Events.Add(value);
+    }
+
+    [Fact]
+    public void EvaluationProgressSurvivesButUnverifiedCommitsNeverEscape()
+    {
+        var request = Request("stub");
+        var progress = new CollectProgress();
+        var result = NestPipeline.RunCutoutPreview(new ProgressStub(), "stub", request, progress);
+        Assert.False(result.CanKeep);
+        Assert.Single(progress.Events);
+        Assert.Equal(NestJobStage.EvaluatingCandidate, progress.Events[0].Stage);
+        Assert.Equal(0, progress.Events[0].CommittedPlates);
+        Assert.Equal(0, progress.Events[0].CommittedParts);
+    }
+
+    private sealed class ProgressStub : INestingEngine
+    {
+        public NestJobResult Solve(NestJob job, IProgress<NestJobProgress>? progress = null,
+            CancellationToken token = default)
+        {
+            progress?.Report(new NestJobProgress(NestJobStage.EvaluatingCandidate,
+                job.Plates[0].Id, 0, 1, 1));
+            progress?.Report(new NestJobProgress(NestJobStage.PlateCommitted,
+                job.Plates[0].Id, 0, 1, 1));
+            return Result(job);
+        }
+    }
+
+    [Fact]
+    public void ReorderedButContiguousEngineIndicesAreAccepted()
+    {
+        var request = Request("stub");
+        request.Items[1].Quantity = 3;
+        request.Items[1].Drawing.Program = TestShapes.Rectangle(6, 6);
+        request = request with { Stock = new[] { new NestPlateStock("sheet", new Size(30, 30), 1, 0.25) } };
+        var result = NestPipeline.RunCutoutPreview(new Stub(job =>
+        {
+            var proxy = job.Parts.Single(p => p.Id.StartsWith("__cutout-proxy-"));
+            Assert.Equal(2, job.Parts.Single(p => p.Id == "part-1").Quantity);
+            return Result(job, new NestJobPlacement(proxy.Id, 0, 11, 11, 0),
+                new NestJobPlacement("part-1", 1, 22, 1, 0),
+                new NestJobPlacement("part-1", 0, 22, 9, 0));
+        }), "stub", request);
+        Assert.True(result.IsValid, string.Join("; ", result.Violations));
+        Assert.Equal(new[] { 0, 1, 2 }, result.Raw.Plates.Single().Placements
+            .Where(p => p.PartId == "part-1").Select(p => p.InstanceIndex));
+    }
+
+    [Theory]
+    [InlineData(true)]
+    [InlineData(false)]
+    public void ForgedFulfillmentOrStockMetadataCannotBind(bool fulfillment)
+    {
+        var request = Request("stub");
+        var result = NestPipeline.RunCutoutPreview(new Stub(job =>
+        {
+            var proxy = job.Parts.Single(p => p.Id.StartsWith("__cutout-proxy-"));
+            var good = Result(job, new NestJobPlacement(proxy.Id, 0, 11, 11, 0));
+            return new NestJobResult(good.Status, good.StopReason, good.Plates,
+                fulfillment ? new[] { new PartFulfillment(proxy.Id, 1, 0, 1) } : good.Fulfillment,
+                fulfillment ? good.StockUsage : new[] { new StockUsage("sheet", 0, 1) });
+        }), "stub", request);
+        Assert.False(result.CanKeep);
+        Assert.Empty(result.Plates);
+        Assert.Contains(result.Violations, v => v.Contains("accounting"));
+    }
+
+    [Fact]
+    public void SameDrawingInTwoRequirementRowsRetainsSeparateIds()
+    {
+        var initial = Request("stub");
+        var request = initial with
+        {
+            Items = new[] { initial.Items[0], initial.Items[1],
+            new NestItem { Drawing = initial.Items[1].Drawing, Quantity = 1 } },
+            Stock = new[] { new NestPlateStock("sheet", new Size(30, 30), 1, 0.25) }
+        };
+        var result = NestPipeline.RunCutoutPreview(new Stub(job =>
+        {
+            var proxy = job.Parts.Single(p => p.Id.StartsWith("__cutout-proxy-"));
+            var residual = job.Parts.Where(p => p.Id != proxy.Id)
+                .Select((p, i) => new NestJobPlacement(p.Id, 0, 22, 1 + 5 * i, 0));
+            return Result(job, new[] { new NestJobPlacement(proxy.Id, 0, 11, 11, 0) }
+                .Concat(residual).ToArray());
+        }), "stub", request);
+        Assert.True(result.IsValid, string.Join("; ", result.Violations));
+        Assert.Equal(new[] { "part-0", "part-1", "part-2" },
+            result.Raw.Plates.Single().Placements.Select(p => p.PartId));
+        Assert.Same(result.Plates.Single().Parts[1].BaseDrawing,
+            result.Plates.Single().Parts[2].BaseDrawing);
+    }
+
+    [Fact]
+    public void RepeatedFrameReservationsExpandOnTwoPhysicalSheets()
+    {
+        var request = Request("stub");
+        request.Items[0].Quantity = 2;
+        request.Items[1].Quantity = 2;
+        request.Items[1].Drawing.Program = TestShapes.Rectangle(6, 6);
+        request = request with
+        {
+            Stock = new[] { new NestPlateStock("sheet", new Size(22, 22), 2, 0.25) },
+            Options = new NestJobOptions(maxPlates: 2)
+        };
+        var calls = 0;
+        var result = NestPipeline.RunCutoutPreview(new Stub(job =>
+        {
+            calls++;
+            var proxies = job.Parts.Where(p => p.Id.StartsWith("__cutout-proxy-")).ToArray();
+            Assert.Equal(2, proxies.Length);
+            Assert.Equal(2, job.Parts.Count);
+            var builder = new NestJobResultBuilder(job);
+            foreach (var proxy in proxies)
+                builder.AddSheet(job.Plates[0], new[] { (proxy.Id, 11.0, 11.0, 0.0) });
+            return builder.Build(NestJobStopReason.Completed);
+        }), "stub", request);
+        Assert.Equal(1, calls);
+        Assert.True(result.IsValid, string.Join("; ", result.Violations));
+        Assert.Equal(2, result.Raw.Plates.Count);
+        Assert.All(result.Raw.Plates, plate => Assert.Equal(new[] { "part-0", "part-1" },
+            plate.Placements.Select(p => p.PartId)));
+        Assert.All(result.Raw.Fulfillment, f => Assert.Equal((2, 2, 0),
+            (f.Requested, f.Placed, f.Unplaced)));
+        Assert.Equal(new[] { 0, 1 }, result.Raw.Plates.SelectMany(p => p.Placements)
+            .Where(p => p.PartId == "part-1").Select(p => p.InstanceIndex));
+    }
+
+    [Fact]
+    public void UnplacedFrameReleasesInsertDemandWithoutABindablePartialProposal()
+    {
+        var request = Request("stub");
+        request.Items[0].Quantity = 2;
+        request.Items[1].Quantity = 2;
+        request.Items[1].Drawing.Program = TestShapes.Rectangle(6, 6);
+        request = request with { Stock = new[] { new NestPlateStock("sheet", new Size(22, 22), 2, 0.25) } };
+        var calls = 0;
+        var result = NestPipeline.RunCutoutPreview(new Stub(job =>
+        {
+            calls++;
+            var first = job.Parts.Single(p => p.Id.EndsWith("-0"));
+            var builder = new NestJobResultBuilder(job);
+            builder.AddSheet(job.Plates[0], new[] { (first.Id, 11.0, 11.0, 0.0) });
+            return builder.Build(NestJobStopReason.NoPlacementFound);
+        }), "stub", request);
+        Assert.Equal(1, calls);
+        Assert.False(result.CanKeep);
+        Assert.Empty(result.Plates);
+        Assert.Equal(NestJobStatus.Incomplete, result.Raw.Status);
+        Assert.All(result.Raw.Fulfillment, f => Assert.Equal((2, 1, 1),
+            (f.Requested, f.Placed, f.Unplaced)));
+        Assert.Equal(new[] { "part-0", "part-1" }, result.Raw.Plates.Single().Placements.Select(p => p.PartId));
+        AssertCannotCommit(result, request);
+    }
+
+    [Fact]
+    public void DifferentFrameRequirementsShareScarceInsertsByIdentity()
+    {
+        var initial = Request("stub");
+        var frame2 = new Drawing("second-frame", TestShapes.Ring(18, 10));
+        initial.Items[1].Quantity = 2;
+        initial.Items[1].Drawing.Program = TestShapes.Rectangle(6, 6);
+        var request = initial with
+        {
+            Items = new[] { initial.Items[0],
+            new NestItem { Drawing = frame2, Quantity = 1 }, initial.Items[1] },
+            Stock = new[] { new NestPlateStock("sheet", new Size(22, 22), 2, 0.25) }
+        };
+        var result = NestPipeline.RunCutoutPreview(new Stub(job =>
+        {
+            var proxies = job.Parts.Where(p => p.Id.StartsWith("__cutout-proxy-")).ToArray();
+            Assert.Equal(2, proxies.Length);
+            Assert.Equal(2, job.Parts.Count);
+            var builder = new NestJobResultBuilder(job);
+            foreach (var proxy in proxies)
+                builder.AddSheet(job.Plates[0], new[] { (proxy.Id, 11.0, 11.0, 0.0) });
+            return builder.Build(NestJobStopReason.Completed);
+        }), "stub", request);
+        Assert.True(result.IsValid, string.Join("; ", result.Violations));
+        Assert.Equal(new[] { "part-0", "part-2", "part-1", "part-2" },
+            result.Raw.Plates.SelectMany(p => p.Placements).Select(p => p.PartId));
+        Assert.Equal(new[] { 0, 1 }, result.Raw.Plates.SelectMany(p => p.Placements)
+            .Where(p => p.PartId == "part-2").Select(p => p.InstanceIndex));
+    }
+
+    [Fact]
+    public void FixedQuarterTurnComposesLocalInsertRotationAndTranslation()
+    {
+        var frame = TestShapes.Rectangle(20, 20);
+        frame.MoveTo(5, 5);
+        frame.LineTo(5, 15);
+        frame.LineTo(15, 15);
+        frame.LineTo(15, 5);
+        frame.LineTo(5, 5);
+        var quarter = System.Math.PI / 2;
+        var request = new NestPipelineRequest("stub", new[] {
+            new NestItem { Drawing = new Drawing("frame", frame), Quantity = 1,
+                StepAngle = quarter, RotationStart = quarter, RotationEnd = quarter },
+            new NestItem { Drawing = new Drawing("insert", TestShapes.Rectangle(3, 3)), Quantity = 1,
+                StepAngle = quarter, RotationStart = quarter, RotationEnd = quarter } },
+            new[] { new NestPlateStock("sheet", new Size(22, 22), 1, 0.25) });
+        var result = NestPipeline.RunCutoutPreview(new Stub(job =>
+        {
+            var proxy = Assert.Single(job.Parts);
+            Assert.True(proxy.Rotation.Allows(quarter));
+            Assert.False(proxy.Rotation.Allows(0));
+            return Result(job, new NestJobPlacement(proxy.Id, 0, 21, 1, quarter));
+        }), "stub", request);
+        Assert.True(result.IsValid, string.Join("; ", result.Violations));
+        var poses = result.Raw.Plates.Single().Placements;
+        Assert.Equal(quarter, poses[0].Rotation, 8);
+        Assert.Equal(quarter, poses[1].Rotation, 8);
+        // Independent square-hole oracle, not the production clearance predicate.
+        var localX = poses[1].Y - poses[0].Y;
+        var localY = -(poses[1].X - poses[0].X);
+        foreach (var dx in new[] { 0.0, 3.0 })
+            foreach (var dy in new[] { 0.0, 3.0 })
+            {
+                Assert.InRange(localX + dx, 5.25, 14.75);
+                Assert.InRange(localY + dy, 5.25, 14.75);
+            }
+    }
+
+    [Fact]
+    public void HeterogeneousStockUsesConservativeSpacingAndOriginalQuadrant()
+    {
+        var request = Request("stub") with
+        {
+            Stock = new[] {
+            new NestPlateStock("tight", new Size(22, 22), 1, 0.25),
+            new NestPlateStock("wide", new Size(22, 22), 1, 0.6, quadrant: 3) }
+        };
+        var result = NestPipeline.RunCutoutPreview(new Stub(job =>
+        {
+            var proxy = Assert.Single(job.Parts);
+            var builder = new NestJobResultBuilder(job);
+            builder.AddSheet(job.Plates[1], new[] { (proxy.Id, -11.0, -11.0, 0.0) });
+            return builder.Build(NestJobStopReason.Completed);
+        }), "stub", request);
+        Assert.True(result.IsValid, string.Join("; ", result.Violations));
+        Assert.Equal("wide", result.Raw.Plates.Single().StockId);
+        Assert.Equal(3, result.Plates.Single().Stock.Quadrant);
+        Assert.Equal(0.6, result.Plates.Single().Stock.PartSpacing);
+        Assert.Equal(2, result.Plates.Single().Parts.Count);
+    }
+
+    [Fact]
+    public void RegisteredPluginRunsTheSamePhysicalExpansionBoundary()
+    {
+        var name = "CutoutPlugin-" + Guid.NewGuid().ToString("N");
+        var calls = 0;
+        NestingEngineRegistry.Register(name, "test plugin", () => new Stub(job =>
+        {
+            calls++;
+            var proxy = Assert.Single(job.Parts);
+            return Result(job, new NestJobPlacement(proxy.Id, 0, 11, 11, 0));
+        }));
+        try
+        {
+            var result = NestPipeline.RunCutoutPreview(Request(name));
+            Assert.Equal(1, calls);
+            Assert.True(result.IsValid, string.Join("; ", result.Violations));
+            Assert.Equal(new[] { "part-0", "part-1" },
+                result.Raw.Plates.Single().Placements.Select(p => p.PartId));
+        }
+        finally
+        {
+            var registry = Assert.IsType<List<NestingEngineInfo>>(NestingEngineRegistry.AvailableEngines);
+            Assert.Equal(1, registry.RemoveAll(info => info.Name == name));
+        }
+    }
+
+    [Fact]
+    public void TwoCutoutsReserveDifferentCopiesWithinOneFrame()
+    {
+        var program = TestShapes.Rectangle(20, 20);
+        foreach (var origin in new[] { 2.0, 12.0 })
+        {
+            program.MoveTo(origin, origin);
+            program.LineTo(origin, origin + 6);
+            program.LineTo(origin + 6, origin + 6);
+            program.LineTo(origin + 6, origin);
+            program.LineTo(origin, origin);
+        }
+        var frame = new Drawing("two-hole-frame", program);
+        var insert = new Drawing("insert", TestShapes.Rectangle(4, 4));
+        var request = new NestPipelineRequest("stub", new[] {
+            new NestItem { Drawing = frame, Quantity = 1 },
+            new NestItem { Drawing = insert, Quantity = 2 } },
+            new[] { new NestPlateStock("sheet", new Size(22, 22), 1, 0.25) });
+        var result = NestPipeline.RunCutoutPreview(new Stub(job =>
+        {
+            var proxy = Assert.Single(job.Parts);
+            return Result(job, new NestJobPlacement(proxy.Id, 0, 1, 1, 0));
+        }), "stub", request);
+        Assert.True(result.IsValid, string.Join("; ", result.Violations));
+        var inserts = result.Raw.Plates.Single().Placements.Skip(1).ToArray();
+        Assert.Equal(2, inserts.Length);
+        Assert.All(inserts, p =>
+        {
+            var localX = p.X - 1;
+            var localY = p.Y - 1;
+            Assert.Contains(new[] { 2.0, 12.0 }, origin =>
+                localX >= origin + 0.25 && localX + 4 <= origin + 5.75
+                && localY >= origin + 0.25 && localY + 4 <= origin + 5.75);
+        });
+    }
+
+    [Fact]
+    public void DifferentPrioritiesRemainIndependentInsteadOfElevatingAnInsert()
+    {
+        var request = Request("stub");
+        request.Items[1].Priority = 3;
+        var result = NestPipeline.RunCutoutPreview(new Stub(job =>
+        {
+            Assert.DoesNotContain(job.Parts, p => p.Id.StartsWith("__cutout-proxy-"));
+            return Result(job);
+        }), "stub", request);
+        Assert.True(result.CanKeep);
+        Assert.Empty(result.Plates);
+    }
+
+    [Theory]
+    [InlineData(1, 11.0, 11.0)]
+    [InlineData(2, -11.0, 11.0)]
+    [InlineData(3, -11.0, -11.0)]
+    [InlineData(4, 11.0, -11.0)]
+    public void AllQuadrantsKeepPhysicalStockAndExpansion(int quadrant, double x, double y)
+    {
+        var request = Request("stub") with
+        {
+            Stock = new[] {
+            new NestPlateStock("sheet", new Size(22, 22), 1, 0.25,
+                new Spacing(0.5, 0.5), quadrant) },
+            Options = new NestJobOptions(maxPlates: 1)
+        };
+        var result = NestPipeline.RunCutoutPreview(new Stub(job =>
+            Result(job, new NestJobPlacement(Assert.Single(job.Parts).Id, 0, x, y, 0))),
+            "stub", request);
+        Assert.True(result.IsValid, string.Join("; ", result.Violations));
+        Assert.Equal(quadrant, result.Plates.Single().Stock.Quadrant);
+        Assert.Equal((x, y), (result.Raw.Plates.Single().Placements[0].X,
+            result.Raw.Plates.Single().Placements[0].Y));
+    }
+
+    [Fact]
+    public void CancellationAfterAnEngineIgnoresStopDiscardsEveryBundle()
+    {
+        var request = Request("stub");
+        using var cts = new CancellationTokenSource();
+        Assert.Throws<OperationCanceledException>(() => NestPipeline.RunCutoutPreview(
+            new Stub(job =>
+            {
+                var proxy = Assert.Single(job.Parts);
+                cts.Cancel();
+                return Result(job, new NestJobPlacement(proxy.Id, 0, 11, 11, 0));
+            }), "stub", request, token: cts.Token));
+        Assert.All(request.Items, item => Assert.Equal(0, item.Drawing.Quantity.Nested));
+    }
+
+    [Fact]
+    public void CompleteStatusWithMissingProxyIsUntrustedAndNotBindable()
+    {
+        var request = Request("stub");
+        var result = NestPipeline.RunCutoutPreview(new Stub(job => new NestJobResult(
+            NestJobStatus.Complete, NestJobStopReason.Completed,
+            Array.Empty<NestJobPlateResult>(),
+            job.Parts.Select(p => new PartFulfillment(p.Id, p.Quantity, 0, p.Quantity)),
+            job.Plates.Select(s => new StockUsage(s.Id, 0, s.Quantity)))), "stub", request);
+        Assert.False(result.CanKeep);
+        Assert.Empty(result.Plates);
+        Assert.Contains(result.Violations, v => v.Contains("accounting"));
+        AssertCannotCommit(result, request);
+    }
+
+    [Fact]
+    public void SuccessfulCompositeReportsOnlyValidatedPhysicalCommitCounts()
+    {
+        var request = Request("stub");
+        var progress = new CollectProgress();
+        var result = NestPipeline.RunCutoutPreview(new ReportingStub(), "stub", request, progress);
+        Assert.True(result.IsValid, string.Join("; ", result.Violations));
+        Assert.Equal(new[] { NestJobStage.EvaluatingCandidate, NestJobStage.PlateCommitted },
+            progress.Events.Select(e => e.Stage));
+        Assert.Equal(2, progress.Events.Last().CommittedParts);
+        Assert.Equal(1, progress.Events.Last().CommittedPlates);
+    }
+
+    private sealed class ReportingStub : INestingEngine
+    {
+        public NestJobResult Solve(NestJob job, IProgress<NestJobProgress>? progress = null,
+            CancellationToken token = default)
+        {
+            var proxy = Assert.Single(job.Parts);
+            progress?.Report(new NestJobProgress(NestJobStage.EvaluatingCandidate,
+                job.Plates[0].Id, 0, 0, 0));
+            progress?.Report(new NestJobProgress(NestJobStage.PlateCommitted,
+                job.Plates[0].Id, 0, 1, 1));
+            return Result(job, new NestJobPlacement(proxy.Id, 0, 11, 11, 0));
+        }
+    }
+
+    [Fact]
+    public void AutomaticBundleRetainsStockFeasibleQuarterTurn()
+    {
+        var program = TestShapes.Rectangle(20, 10);
+        program.MoveTo(2, 2);
+        program.LineTo(2, 8);
+        program.LineTo(18, 8);
+        program.LineTo(18, 2);
+        program.LineTo(2, 2);
+        var request = new NestPipelineRequest("Irregular", new[] {
+            new NestItem { Drawing = new Drawing("long-frame", program), Quantity = 1 },
+            new NestItem { Drawing = new Drawing("insert", TestShapes.Rectangle(3, 3)), Quantity = 1 } },
+            new[] { new NestPlateStock("narrow", new Size(22, 12), 1, 0.25) });
+        var result = NestPipeline.RunCutoutPreview(request);
+        Assert.True(result.IsValid, string.Join("; ", result.Violations));
+        var frame = result.Raw.Plates.Single().Placements[0];
+        Assert.Equal(System.Math.PI / 2, frame.Rotation, 7);
+        Assert.Equal(new[] { "part-0", "part-1" },
+            result.Raw.Plates.Single().Placements.Select(p => p.PartId));
+    }
+
+    [Fact]
+    public void ChangedLiveInsertDuringSolveNeverBindsUncheckedComposite()
+    {
+        var request = Request("stub");
+        var result = NestPipeline.RunCutoutPreview(new Stub(job =>
+        {
+            request.Items[1].Drawing.Program = TestShapes.Rectangle(40, 40);
+            var proxy = Assert.Single(job.Parts);
+            return Result(job, new NestJobPlacement(proxy.Id, 0, 11, 11, 0));
+        }), "stub", request);
+        Assert.False(result.CanKeep);
+        Assert.Empty(result.Plates);
+        Assert.Contains(result.Violations, v => v.Contains("changed") && v.Contains("insert"));
+        AssertCannotCommit(result, request);
+    }
+
+    [Fact]
+    public void NondefaultOptionsPassUnchangedAndPlateCapRejectsOtherwiseValidOutput()
+    {
+        var request = Request("stub");
+        request.Items[0].Quantity = 2;
+        request.Items[1].Quantity = 2;
+        request.Items[1].Drawing.Program = TestShapes.Rectangle(6, 6);
+        var options = new NestJobOptions("Strip", maxPlates: 1,
+            salvageRate: 0.4, minimumSalvageDimension: 2);
+        request = request with
+        {
+            Stock = new[] { new NestPlateStock("sheet", new Size(22, 22), 2, 0.25) },
+            Options = options
+        };
+        var result = NestPipeline.RunCutoutPreview(new Stub(job =>
+        {
+            Assert.Same(options, job.Options);
+            Assert.Equal("Strip", job.Options.PlacementStrategy);
+            Assert.Equal(0.4, job.Options.SalvageRate);
+            var builder = new NestJobResultBuilder(job);
+            foreach (var proxy in job.Parts)
+                builder.AddSheet(job.Plates[0], new[] { (proxy.Id, 11.0, 11.0, 0.0) });
+            return builder.Build(NestJobStopReason.Completed);
+        }), "stub", request);
+        Assert.False(result.CanKeep);
+        Assert.Empty(result.Plates);
+        Assert.Contains(result.Violations, v => v.Contains("MaxPlates"));
+        AssertCannotCommit(result, request);
+    }
+
+    [Fact]
+    public void ObliqueFramePreservesLegalGlobalInsertRotationAndWallClearance()
+    {
+        var program = TestShapes.Rectangle(20, 20);
+        program.MoveTo(5, 5);
+        program.LineTo(5, 15);
+        program.LineTo(15, 15);
+        program.LineTo(15, 5);
+        program.LineTo(5, 5);
+        const double angle = 0.3;
+        var request = new NestPipelineRequest("stub", new[] {
+            new NestItem { Drawing = new Drawing("frame", program), Quantity = 1,
+                StepAngle = 1, RotationStart = angle, RotationEnd = angle },
+            new NestItem { Drawing = new Drawing("insert", TestShapes.Rectangle(3, 3)),
+                Quantity = 1, StepAngle = 1, RotationStart = angle, RotationEnd = angle } },
+            new[] { new NestPlateStock("sheet", new Size(40, 40), 1, 0.25) });
+        var result = NestPipeline.RunCutoutPreview(new Stub(job =>
+            Result(job, new NestJobPlacement(Assert.Single(job.Parts).Id, 0, 15, 5, angle))),
+            "stub", request);
+        Assert.True(result.IsValid, string.Join("; ", result.Violations));
+        var poses = result.Raw.Plates.Single().Placements;
+        Assert.Equal(angle, poses[1].Rotation, 8);
+        var dx = poses[1].X - poses[0].X;
+        var dy = poses[1].Y - poses[0].Y;
+        var cosine = System.Math.Cos(angle);
+        var sine = System.Math.Sin(angle);
+        var localX = dx * cosine + dy * sine;
+        var localY = -dx * sine + dy * cosine;
+        foreach (var x in new[] { 0.0, 3.0 })
+            foreach (var y in new[] { 0.0, 3.0 })
+            {
+                Assert.InRange(localX + x, 5.25, 14.75);
+                Assert.InRange(localY + y, 5.25, 14.75);
+            }
+    }
+
+    [Fact]
+    public void LargeDemandLeavesExcessFramesAndInsertsIndependentAfterBoundedPreparation()
+    {
+        var frame = TestShapes.Rectangle(20, 20);
+        frame.MoveTo(5, 5);
+        frame.LineTo(5, 15);
+        frame.LineTo(15, 15);
+        frame.LineTo(15, 5);
+        frame.LineTo(5, 5);
+        var request = new NestPipelineRequest("stub", new[] {
+            new NestItem { Drawing = new Drawing("frame", frame), Quantity = 40,
+                StepAngle = 1, RotationStart = 0, RotationEnd = 0 },
+            new NestItem { Drawing = new Drawing("insert", TestShapes.Rectangle(6, 6)),
+                Quantity = 40, StepAngle = 1, RotationStart = 0, RotationEnd = 0 } },
+            new[] { new NestPlateStock("sheet", new Size(22, 22), 40, 0.25) });
+        var result = NestPipeline.RunCutoutPreview(new Stub(job =>
+        {
+            Assert.Equal(32, job.Parts.Count(p => p.Id.StartsWith("__cutout-proxy-")));
+            Assert.Equal(8, job.Parts.Single(p => p.Id == "part-0").Quantity);
+            Assert.Equal(8, job.Parts.Single(p => p.Id == "part-1").Quantity);
+            return Result(job);
+        }), "stub", request);
+        Assert.False(result.CanKeep);
+        Assert.All(result.Raw.Fulfillment, f => Assert.Equal((40, 0, 40),
+            (f.Requested, f.Placed, f.Unplaced)));
+    }
+
+    [Fact]
+    public void OrdinaryPipelineIsStillUnchanged()
+    {
+        var request = Request("stub");
+        var result = NestPipeline.Run(new Stub(job =>
+        {
+            Assert.DoesNotContain(job.Parts, p => p.Id.StartsWith("__cutout-proxy-"));
+            return Result(job);
+        }), "stub", request);
+        Assert.True(result.CanKeep);
+        Assert.Empty(result.Plates);
+    }
+}

OpenNest.Engine.Tests/Jobs/Cutouts/CutoutRouterTests.cs

@@ -0,0 +1,228 @@
+using OpenNest.Engine.Jobs;
+using OpenNest.Engine.Jobs.Cutouts;
+using OpenNest.Engine.Tests.NestingEngines;
+using TestShapes = OpenNest.Engine.Tests.NestingEngines.Shapes;
+
+namespace OpenNest.Engine.Tests.Jobs.Cutouts;
+
+public class CutoutRouterTests
+{
+    private static NestJobPart Frame()
+    {
+        var program = TestShapes.Rectangle(20, 20);
+        program.MoveTo(5, 5);
+        program.LineTo(5, 15);
+        program.LineTo(15, 15);
+        program.LineTo(15, 5);
+        program.LineTo(5, 5);
+        return JobBuilder.Part("frame", program, 1);
+    }
+
+    [Fact]
+    public void SmallLatticeAndLargeResidualKeepTheirOriginalRequirementIds()
+    {
+        var frame = JobBuilder.Part("frame", TestShapes.Ring(20, 10), 1);
+        var small = JobBuilder.Part("small", TestShapes.Rectangle(1, 1), 3);
+        var large = JobBuilder.Rectangle("large", 3, 3, 1, RotationPolicy.Fixed(0));
+        var origins = new List<(NestJobPlacement Pose, bool Lattice)>();
+        var poses = CutoutRouter.Fill(frame, 0, new[] { small, large }, 0.25,
+            (pose, lattice) => origins.Add((pose, lattice)));
+        Assert.Equal(3, poses.Count(p => p.PartId == small.Id));
+        Assert.Single(poses, p => p.PartId == large.Id);
+        Assert.Contains(origins, row => row.Pose.PartId == small.Id && row.Lattice);
+        Assert.Contains(origins, row => row.Pose.PartId == large.Id && !row.Lattice);
+        Assert.Equal(poses, origins.Select(row => row.Pose));
+        Assert.Equal(new[] { 0, 1, 2 }, poses.Where(p => p.PartId == small.Id).Select(p => p.InstanceIndex));
+        AssertPhysical(frame, new[] { small, large }, poses);
+    }
+
+    [Fact]
+    public void ImpossibleRemainderNeverDisplacesCertifiedCopies()
+    {
+        var frame = Frame();
+        var small = JobBuilder.Rectangle("small", 1, 1, 3, RotationPolicy.Fixed(0));
+        var impossible = JobBuilder.Rectangle("impossible", 9.6, 9.6, 1, RotationPolicy.Fixed(0));
+        var together = CutoutRouter.Fill(frame, 0, new[] { small, impossible }, 0.25);
+        Assert.Equal(3, together.Count);
+        Assert.All(together, p => Assert.Equal(small.Id, p.PartId));
+        Assert.Equal(Enumerable.Range(0, 3), together.Select(p => p.InstanceIndex));
+        AssertPhysical(frame, new[] { small, impossible }, together);
+    }
+
+    [Fact]
+    public void PriorCopiesAndQuantityCannotBeBypassedByResidualSearch()
+    {
+        var frame = Frame();
+        var small = JobBuilder.Rectangle("small", 2, 2, 4, RotationPolicy.Fixed(0));
+        var large = JobBuilder.Rectangle("large", 7, 7, 1, RotationPolicy.Fixed(0));
+        var poses = CutoutRouter.Fill(frame, 0, new[] { small, large }, 0.25);
+        Assert.InRange(poses.Count(p => p.PartId == small.Id), 0, small.Quantity);
+        Assert.InRange(poses.Count(p => p.PartId == large.Id), 0, large.Quantity);
+        AssertPhysical(frame, new[] { small, large }, poses);
+    }
+
+    [Fact]
+    public void ResidualNfpDoesNotOverlapTheFirstLargeInsert()
+    {
+        var frame = Frame();
+        var insert = JobBuilder.Rectangle("large", 6, 6, 2, RotationPolicy.Fixed(0));
+        var poses = CutoutRouter.Fill(frame, 0, new[] { insert }, 0.25);
+        Assert.Single(poses);
+        AssertPhysical(frame, new[] { insert }, poses);
+    }
+
+    [Fact]
+    public void NfpAddsOneMoreCopyToPartialShiftedLattice()
+    {
+        // Neutral 8-inch round hole, 2x1 insert, quarter-inch spacing: the shifted
+        // lattice keeps 11; an independently certified NFP pose occupies its leftover.
+        var frame = JobBuilder.Part("frame", TestShapes.Ring(18, 8), 1);
+        var insert = JobBuilder.Part("insert", TestShapes.Rectangle(2, 1), 12);
+        var origins = new List<(NestJobPlacement Pose, bool Lattice)>();
+        var poses = CutoutRouter.Fill(frame, 0, new[] { insert }, 0.25,
+            (pose, lattice) => origins.Add((pose, lattice)));
+        Assert.Equal(12, poses.Count);
+        Assert.Equal(11, origins.Count(row => row.Lattice));
+        Assert.Single(origins, row => !row.Lattice);
+        Assert.Equal(poses, origins.Select(row => row.Pose));
+        Assert.Equal(Enumerable.Range(0, 12), poses.Select(p => p.InstanceIndex));
+        AssertPhysical(frame, new[] { insert }, poses);
+    }
+
+    [Fact]
+    public void MiddleRatioChoosesTwoLatticeCopiesOverOneNfpCopy()
+    {
+        // 4x4 / (pi*5^2) = 0.204. A hard NFP-only threshold at 0.20 loses one copy.
+        var frame = JobBuilder.Part("frame", TestShapes.Ring(20, 10), 1);
+        var insert = JobBuilder.Part("insert", TestShapes.Rectangle(4, 4), 3);
+        Assert.InRange(16 / (System.Math.PI * 25), CutoutRouter.SmallRatio, CutoutRouter.LargeRatio);
+        var poses = CutoutRouter.Fill(frame, 0, new[] { insert }, 0.25);
+        Assert.Equal(2, poses.Count);
+        AssertPhysical(frame, new[] { insert }, poses);
+    }
+
+    [Fact]
+    public void LargeRatioKeepsAnNfpPoseWhenFillCannotProduceALattice()
+    {
+        var frame = JobBuilder.Part("frame", TestShapes.Ring(18, 8), 1);
+        var insert = JobBuilder.Rectangle("insert", 4.5, 4.5, 3, RotationPolicy.Fixed(0));
+        Assert.True(20.25 / (System.Math.PI * 16) > CutoutRouter.LargeRatio);
+        Assert.Empty(CutoutLatticeFill.Fill(frame, 0, insert, 3, 0.25));
+        var poses = CutoutRouter.Fill(frame, 0, new[] { insert }, 0.25);
+        Assert.Single(poses);
+        AssertPhysical(frame, new[] { insert }, poses);
+    }
+
+    [Fact]
+    public void DuplicateRequirementIdsAreRejectedBeforePlacement()
+    {
+        var frame = Frame();
+        var insert = JobBuilder.Rectangle("same", 1, 1, 3);
+        Assert.Throws<ArgumentException>(() => CutoutRouter.Fill(frame, 0,
+            new[] { insert, insert }, 0.25));
+    }
+
+    [Fact]
+    public void OccupiedAwareLatticeFillsAfterAnEarlierCopyBlocksItsFirstPose()
+    {
+        var frame = JobBuilder.Part("frame", TestShapes.Ring(20, 10), 1);
+        var first = JobBuilder.Part("first", TestShapes.Rectangle(1, 1), 1);
+        var more = JobBuilder.Part("more", TestShapes.Rectangle(1, 1), 3);
+        var early = CutoutLatticeFill.Fill(frame, 0, more, 3, 0.25);
+        Assert.Equal(3, early.Count);
+        var blocked = early[0] with { PartId = first.Id };
+        var occupied = new[] { (JobPartGeometry.Read(first.Geometry), blocked) };
+        var later = CutoutLatticeFill.Fill(frame, 0, more, 3, 0.25,
+            CutoutLatticeFill.DefaultShiftSteps, occupied, default);
+        Assert.Equal(3, later.Count);
+        Assert.All(later, p => Assert.True(NestLayoutCheck.Clears(occupied[0].Item1, blocked,
+            JobPartGeometry.Read(more.Geometry), p, 0.25)));
+    }
+
+    [Fact]
+    public void TinyInsertDoesNotAllocateAnUnboundedLattice()
+    {
+        var frame = Frame();
+        var tiny = JobBuilder.Rectangle("tiny", 0.001, 0.001, 3, RotationPolicy.Fixed(0));
+        Assert.Empty(CutoutLatticeFill.Fill(frame, 0, tiny, 3, 0));
+        var poses = CutoutRouter.Fill(frame, 0, new[] { tiny }, 0);
+        Assert.Equal(3, poses.Count);
+    }
+
+    [Fact]
+    public void CancellationIsNotNoFit()
+    {
+        using var cts = new CancellationTokenSource();
+        cts.Cancel();
+        Assert.Throws<OperationCanceledException>(() => CutoutRouter.Fill(Frame(), 0,
+            new[] { JobBuilder.Rectangle("small", 1, 1, 3) }, 0.25, cts.Token));
+    }
+
+    private static void AssertPhysical(NestJobPart frame, NestJobPart[] inserts,
+        IReadOnlyList<NestJobPlacement> poses)
+    {
+        var stock = JobBuilder.Stock("sheet", 22, 22, 0.25);
+        var job = JobBuilder.Job(new[] { frame }.Concat(inserts).ToArray(), new[] { stock });
+        var frameBounds = JobPartGeometry.Read(frame.Geometry).Bounds;
+        var offsetX = 1 - frameBounds.Left;
+        var offsetY = 1 - frameBounds.Bottom;
+        var placements = new[] { new NestJobPlacement(frame.Id, 0, offsetX, offsetY, 0) }
+            .Concat(poses.Select(p => p with { X = p.X + offsetX, Y = p.Y + offsetY })).ToArray();
+        var result = new NestJobResult(NestJobStatus.Complete, NestJobStopReason.Completed,
+            new[] { new NestJobPlateResult(0, stock, placements) },
+            new[] { new PartFulfillment(frame.Id, 1, 1, 0) }
+                .Concat(inserts.Select(part => new PartFulfillment(part.Id, part.Quantity,
+                    poses.Count(p => p.PartId == part.Id), part.Quantity - poses.Count(p => p.PartId == part.Id))))
+                .ToArray(),
+            new[] { new StockUsage(stock.Id, 1, null) });
+        LayoutAssert.Valid(job, result);
+        var frameGeometry = JobPartGeometry.Read(frame.Geometry);
+        var framePose = new NestJobPlacement(frame.Id, 0, 0, 0, 0);
+        foreach (var pose in poses)
+        {
+            var geometry = JobPartGeometry.Read(inserts.Single(p => p.Id == pose.PartId).Geometry);
+            Assert.True(NestLayoutCheck.Clears(frameGeometry, framePose, geometry, pose, 0.25));
+            // Independent square-wall oracle: every corner of each rectangular insert clears the hole.
+            var bounds = geometry.Bounds;
+            foreach (var (x, y) in new[] { (bounds.Left, bounds.Bottom), (bounds.Right, bounds.Bottom),
+                (bounds.Right, bounds.Top), (bounds.Left, bounds.Top) })
+            {
+                var rx = pose.X + x * System.Math.Cos(pose.Rotation) - y * System.Math.Sin(pose.Rotation);
+                var ry = pose.Y + x * System.Math.Sin(pose.Rotation) + y * System.Math.Cos(pose.Rotation);
+                if (frameBounds.Left >= 0)
+                {
+                    Assert.InRange(rx, 5.25, 14.75);
+                    Assert.InRange(ry, 5.25, 14.75);
+                }
+                else
+                {
+                    var radius = System.Math.Abs(frameGeometry.Cutouts[0].BoundingBox.Right);
+                    Assert.True(System.Math.Sqrt(rx * rx + ry * ry) <= radius - 0.25 + 0.00001);
+                }
+            }
+        }
+        // Independent rectangle-vs-rectangle distance, not the production Clears predicate.
+        for (var i = 0; i < poses.Count; i++)
+            for (var j = i + 1; j < poses.Count; j++)
+            {
+                var a = Bounds(poses[i]);
+                var b = Bounds(poses[j]);
+                var dx = System.Math.Max(0, System.Math.Max(a.Left - b.Right, b.Left - a.Right));
+                var dy = System.Math.Max(0, System.Math.Max(a.Bottom - b.Top, b.Bottom - a.Top));
+                Assert.True(System.Math.Sqrt(dx * dx + dy * dy) >= 0.25 - 0.00001,
+                    $"independent material gap too small: {poses[i]} vs {poses[j]}");
+            }
+
+        (double Left, double Right, double Bottom, double Top) Bounds(NestJobPlacement pose)
+        {
+            var box = JobPartGeometry.Read(inserts.Single(p => p.Id == pose.PartId).Geometry).Bounds;
+            var corners = new[] { (box.Left, box.Bottom), (box.Right, box.Bottom),
+                (box.Right, box.Top), (box.Left, box.Top) };
+            var x = corners.Select(c => pose.X + c.Item1 * System.Math.Cos(pose.Rotation)
+                - c.Item2 * System.Math.Sin(pose.Rotation)).ToArray();
+            var y = corners.Select(c => pose.Y + c.Item1 * System.Math.Sin(pose.Rotation)
+                + c.Item2 * System.Math.Cos(pose.Rotation)).ToArray();
+            return (x.Min(), x.Max(), y.Min(), y.Max());
+        }
+    }
+}

OpenNest.Engine.Tests/Jobs/NestJobCostTests.cs

@@ -84,7 +84,14 @@ public class NestJobCostTests
             TestDrawingFactory.Rectangle(4, 3)), 5);
         var cleanJob = new NestJob(new[] { cleanPart }, job.Plates, job.Options);
         foreach (var sheet in result.Plates)
-            Assert.Equal(LegacyNestJobCost.EstimateNetArea(cleanJob, sheet), NestJobCost.NetSheetArea(job, sheet));
+        {
+            var area = LegacyNestJobCost.EstimateNetArea(cleanJob, sheet);
+            Assert.Equal(area, NestJobCost.NetSheetArea(job, sheet));
+            var priced = new NestPlateStock(sheet.Stock.Id, sheet.Stock.Size, sheet.Stock.Quantity,
+                sheet.Stock.PartSpacing, sheet.Stock.EdgeSpacing, sheet.Stock.Quadrant, 37);
+            var pricedSheet = new NestJobPlateResult(sheet.PlateIndex, priced, sheet.Placements);
+            Assert.Equal(37 * (area / sheet.Stock.Area), NestJobCost.NetSheetCost(job, pricedSheet));
+        }
         Assert.Equal(2500, NestJobCost.UnplacedPartPenalty(job));
         Assert.Equal(result.Plates.Sum(sheet => LegacyNestJobCost.EstimateNetArea(cleanJob, sheet)) + 5000,
             NestJobCost.Evaluate(job, result));

OpenNest.Engine.Tests/Jobs/NestPipelineCommitTests.cs

@@ -75,6 +75,73 @@ public class NestPipelineCommitTests
         Assert.Equal(2, Assert.Single(applied).Parts.Count);
     }
 
+    [Fact]
+    public void DrawingChangedAfterValidationIsRefusedBeforeCommitEvenWithConsent()
+    {
+        var drawing = new Drawing("part", TestDrawingFactory.Rectangle());
+        var nest = new Nest();
+        nest.Drawings.Add(drawing);
+        var empty = nest.CreatePlate();
+        using var manager = new PlateManager(nest);
+        var result = NestPipeline.Run(new PreMutationStub(), "stub",
+            new NestPipelineRequest("stub", new[] { new NestItem { Drawing = drawing, Quantity = 1 } },
+                new[] { new NestPlateStock("sheet", new Size(48, 96), 1, 0.25) }));
+        Assert.True(result.IsValid, string.Join("; ", result.Violations));
+        drawing.Program = TestDrawingFactory.Rectangle(100, 100);
+        Assert.Throws<InvalidOperationException>(() =>
+            NestPipelineCommit.ApplyToEmptyPlates(result, manager, allowInvalid: true));
+        Assert.Same(empty, Assert.Single(nest.Plates));
+        Assert.Empty(empty.Parts);
+        Assert.Equal(0, drawing.Quantity.Nested);
+    }
+
+    private sealed class PreMutationStub : INestingEngine
+    {
+        public NestJobResult Solve(NestJob job, IProgress<NestJobProgress>? progress = null,
+            CancellationToken token = default)
+        {
+            var builder = new NestJobResultBuilder(job);
+            builder.AddSheet(job.Plates[0], new[] { (job.Parts[0].Id, 1.0, 1.0, 0.0) });
+            return builder.Build(NestJobStopReason.Completed);
+        }
+    }
+
+    private sealed class CancelDuringSnapshot(double x, double y, CancellationTokenSource source)
+        : OpenNest.CNC.LinearMove(x, y)
+    {
+        public override OpenNest.CNC.CodeType Type
+        {
+            get
+            {
+                source.Cancel();
+                return base.Type;
+            }
+        }
+    }
+
+    [Fact]
+    public void CancellationDuringFreshnessScanDoesNotMutateNest()
+    {
+        var drawing = new Drawing("part", TestDrawingFactory.Rectangle());
+        var nest = new Nest();
+        nest.Drawings.Add(drawing);
+        var empty = nest.CreatePlate();
+        using var manager = new PlateManager(nest);
+        var result = NestPipeline.Run(new PreMutationStub(), "stub",
+            new NestPipelineRequest("stub", new[] { new NestItem { Drawing = drawing, Quantity = 1 } },
+                new[] { new NestPlateStock("sheet", new Size(48, 96), 1, 0.25) }));
+        Assert.True(result.IsValid);
+        using var cts = new CancellationTokenSource();
+        var proposed = Assert.Single(Assert.Single(result.Plates).Parts);
+        proposed.Program.Codes[1] = new CancelDuringSnapshot(10, 0, cts);
+        Assert.Throws<OperationCanceledException>(() =>
+            NestPipelineCommit.ApplyToEmptyPlates(result, manager, token: cts.Token));
+        Assert.True(cts.IsCancellationRequested);
+        Assert.Same(empty, Assert.Single(nest.Plates));
+        Assert.Empty(empty.Parts);
+        Assert.Equal(0, drawing.Quantity.Nested);
+    }
+
     [Fact]
     public void CancelledCommitDoesNotCreateAnyPlate()
     {

OpenNest.Engine.Tests/Jobs/NestPipelineTests.cs

@@ -258,6 +258,44 @@ public class NestPipelineTests
         );
     }
 
+    [Fact]
+    public void DrawingChangedDuringSolveCannotBindGeometryOtherThanTheValidatedSnapshot()
+    {
+        var item = Item("bracket", 1);
+        var result = NestPipeline.Run(new StubEngine(job =>
+        {
+            item.Drawing.Program = TestDrawingFactory.Rectangle(100, 100);
+            return OnePlate(job, new NestJobPlacement(job.Parts[0].Id, 0, 1, 1, 0));
+        }), "Mutator", Request("Mutator", item));
+        Assert.False(result.CanKeep);
+        Assert.Empty(result.Plates);
+        Assert.Contains(result.Violations, v => v.Contains("changed") && v.Contains("bracket"));
+    }
+
+    private sealed class TransientCloneMove(double x, double y) : LinearMove(x, y)
+    {
+        public override ICode Clone()
+        {
+            var before = EndPoint;
+            EndPoint = new Vector(100, 100);
+            try { return base.Clone(); }
+            finally { EndPoint = before; }
+        }
+    }
+
+    [Fact]
+    public void BindingTransientDrawingEditCannotReturnOrCommitUncheckedGeometry()
+    {
+        var item = Item("bracket", 1);
+        item.Drawing.Program.Codes[^1] = new TransientCloneMove(0, 0);
+        var result = NestPipeline.Run(new StubEngine(job =>
+            OnePlate(job, new NestJobPlacement(job.Parts[0].Id, 0, 1, 1, 0))),
+            "Transient", Request("Transient", item));
+        Assert.False(result.CanKeep);
+        Assert.Empty(result.Plates);
+        Assert.Contains(result.Violations, v => v.Contains("Bound part") && v.Contains("bracket"));
+    }
+
     [Fact]
     public void CancellationPropagatesWithoutAResult()
     {

OpenNest.Engine.Tests/Jobs/StockCostTests.cs

@@ -0,0 +1,165 @@
+using OpenNest.Engine.Jobs;
+using OpenNest.Geometry;
+
+namespace OpenNest.Engine.Tests.Jobs;
+
+public class StockCostTests
+{
+    public static IEnumerable<object[]> Engines()
+    {
+        foreach (var engine in new[] { "Rectangles", "Irregular", "StockLadder", "Default", "Fill", "Strip", "Vertical Remnant", "Horizontal Remnant" })
+            foreach (var factor in new[] { 1e-12, 1.0, 100.0 })
+                yield return new object[] { engine, factor };
+    }
+
+    private static NestPlateStock Stock(string id, double cost, int quantity = 2, double size = 10) =>
+        new(id, new Size(size, size), quantity, 0.1, default, 1, cost);
+
+    private static NestJob Job(params NestPlateStock[] stocks) => new(
+        new[] { new NestJobPart("part", PartGeometrySnapshot.FromProgram(TestDrawingFactory.Rectangle(4, 4)), 1) }, stocks);
+
+    [Fact]
+    public void ValidationRejectsForgedStockPrice()
+    {
+        var job = Job(Stock("offered", 10));
+        var forged = Stock("offered", 1);
+        var result = new NestJobResult(NestJobStatus.Complete, NestJobStopReason.Completed,
+            new[] { new NestJobPlateResult(0, forged, new[] { new NestJobPlacement("part", 0, 0, 0, 0) }) },
+            Array.Empty<PartFulfillment>(), Array.Empty<StockUsage>());
+        Assert.NotEmpty(NestLayoutCheck.Violations(job, result));
+    }
+
+    [Fact]
+    public void UnavailablePriceDoesNotChangeAreaModeOrLegacyPenalty()
+    {
+        var job = Job(new NestPlateStock("available", new Size(10, 10)), Stock("unavailable", 10000, 0));
+        Assert.False(NestJobCost.UsesExplicitCosts(job));
+        Assert.Equal(100, NestJobCost.UnplacedPartPenalty(job));
+    }
+
+    [Fact]
+    public void FixedStrategyUsesSalvageOnlyForPricedStock()
+    {
+        var poses = new[] { new NestJobPlacement("part", 0, 0, 0, 0) };
+        var candidate = new PlateCandidate(poses);
+        var priced = Job(Stock("small", 10, size: 5), Stock("large", 12, size: 10));
+        var options = new NestJobOptions(salvageRate: 1, minimumSalvageDimension: 1);
+        var pricedJob = new NestJob(priced.Parts, priced.Plates, options);
+        Assert.True(new NestJobCandidateComparer(pricedJob).Compare(candidate, priced.Plates[1], 1,
+            candidate, priced.Plates[0], 0) > 0);
+        var unpriced = new NestJob(priced.Parts, new[] { new NestPlateStock("small", new Size(5, 5)),
+            new NestPlateStock("large", new Size(10, 10)) }, options);
+        Assert.True(new NestJobCandidateComparer(unpriced).Compare(candidate, unpriced.Plates[0], 0,
+            candidate, unpriced.Plates[1], 1) > 0);
+    }
+
+    [Theory]
+    [InlineData(0, 20, 0)]
+    [InlineData(0.5, 14, 6)]
+    public void SummarySeparatesGrossCreditAndNet(double rate, double net, double credit)
+    {
+        var drawing = new Drawing("square", TestDrawingFactory.Rectangle(4, 4));
+        var stock = new NestPlateStock("priced", new Size(10, 10), 1, 0, default, 1, 20);
+        var result = NestPipeline.Run(new NestPipelineRequest("Rectangles",
+            new[] { new NestItem { Drawing = drawing, Quantity = 1 } }, new[] { stock },
+            new NestJobOptions(salvageRate: rate, minimumSalvageDimension: 6)));
+        Assert.Empty(result.Violations);
+        var summary = NestCostSummary.FromAccepted(result);
+        Assert.Equal("supplied-cost", summary.Basis);
+        Assert.Equal(20, summary.GrossTotal);
+        Assert.Equal(net, summary.NetScore, 10);
+        Assert.Equal(credit, summary.SalvageCredit, 10);
+        Assert.Equal(1, Assert.Single(summary.Stock).Used);
+    }
+
+    [Theory]
+    [MemberData(nameof(Engines))]
+    public void PricesReverseSelectionWithoutChangingFulfillment(string engine, double factor)
+    {
+        foreach (var cheap in new[] { "small", "large" })
+        {
+            var job = Job(Stock("small", (cheap == "small" ? 1 : 10) * factor),
+                Stock("large", (cheap == "large" ? 1 : 10) * factor, size: 12));
+            var result = NestingEngineRegistry.Create(engine).Solve(job);
+            Assert.Equal(NestJobStatus.Complete, result.Status);
+            Assert.Empty(NestLayoutCheck.Violations(job, result));
+            Assert.Equal(cheap, Assert.Single(result.Plates).StockId);
+            Assert.Equal(factor, NestJobCost.Evaluate(job, result));
+        }
+    }
+
+    [Theory]
+    [InlineData("Rectangles")]
+    [InlineData("Irregular")]
+    [InlineData("StockLadder")]
+    [InlineData("Default")]
+    [InlineData("Fill")]
+    public void SameSizeStockRetainsIndependentFiniteInventory(string engine)
+    {
+        var stocks = new[] { Stock("expensive", 10, 2, 5), Stock("cheap", 1, 1, 5) };
+        var job = new NestJob(new[] { new NestJobPart("part",
+            PartGeometrySnapshot.FromProgram(TestDrawingFactory.Rectangle(4, 4)), 3) }, stocks);
+        var result = NestingEngineRegistry.Create(engine).Solve(job);
+        Assert.Equal(NestJobStatus.Complete, result.Status);
+        Assert.Empty(NestLayoutCheck.Violations(job, result));
+        Assert.Equal("cheap", result.Plates[0].StockId);
+        Assert.Single(result.Plates.Where(p => p.StockId == "cheap"));
+        Assert.Equal(21, NestJobCost.Evaluate(job, result));
+    }
+
+    [Theory]
+    [InlineData(0)]
+    [InlineData(-1)]
+    [InlineData(double.NaN)]
+    [InlineData(double.PositiveInfinity)]
+    public void ExplicitCostsMustBeFiniteAndPositive(double cost) =>
+        Assert.Throws<ArgumentOutOfRangeException>(() => Stock("bad", cost));
+
+    [Fact]
+    public void MixedModeRejectsOnlyAvailableStock()
+    {
+        Assert.Throws<ArgumentException>(() => Job(Stock("priced", 2), new NestPlateStock("missing", new Size(10, 10))));
+        var job = Job(Stock("priced", 2), new NestPlateStock("unavailable", new Size(10, 10), 0));
+        NestJobValidator.Validate(job);
+        Assert.Equal(2, NestJobCost.UnplacedPartPenalty(job));
+    }
+
+    [Theory]
+    [InlineData(0, 5, 20)]
+    [InlineData(0.5, 0, 20)]
+    [InlineData(0.5, 7, 20)]
+    [InlineData(0.5, 6, 14)]
+    public void PricesCreditSalvageProportionally(double rate, double minimum, double expected)
+    {
+        var stock = new NestPlateStock("priced", new Size(10, 10), 1, 0, default, 1, 20);
+        var job = new NestJob(Job(stock).Parts, new[] { stock }, new NestJobOptions(salvageRate: rate, minimumSalvageDimension: minimum));
+        var sheet = new NestJobPlateResult(0, stock, new[] { new NestJobPlacement("part", 0, 0, 0, 0) });
+        Assert.Equal(expected, NestJobCost.NetSheetCost(job, sheet), 10);
+        Assert.Equal(expected, NestJobCost.NetSheetCost(job.Options, stock, new Box(0, 0, 4, 4)), 10);
+        Assert.Equal(expected * 5, NestJobCost.NetSheetArea(job, sheet), 10);
+    }
+
+    [Fact]
+    public void AggregateOverflowFailsClearly()
+    {
+        var stock = Stock("huge", double.MaxValue);
+        var job = new NestJob(new[] { new NestJobPart("part", PartGeometrySnapshot.FromProgram(TestDrawingFactory.Rectangle(4, 4)), 2) }, new[] { stock });
+        var builder = new NestJobResultBuilder(job);
+        builder.AddSheet(stock, new[] { ("part", 0d, 0d, 0d) });
+        builder.AddSheet(stock, new[] { ("part", 0d, 0d, 0d) });
+        Assert.Throws<OverflowException>(() => NestJobCost.Evaluate(job, builder.Build(NestJobStopReason.Completed)));
+    }
+
+    [Fact]
+    public void BuilderMapsLegacyZeroAndSnapshotsPositiveCosts()
+    {
+        var option = new PlateOption { Width = 10, Length = 10 };
+        Assert.Null(Assert.Single(NestStockBuilder.FromTemplate(new Plate(10, 10), new[] { option })).Cost);
+        option.Cost = 12;
+        var stock = Assert.Single(NestStockBuilder.FromTemplate(new Plate(10, 10), new[] { option }));
+        option.Cost = 50;
+        Assert.Equal(12, stock.Cost);
+        Assert.Throws<ArgumentException>(() => NestStockBuilder.FromTemplate(new Plate(10, 10),
+            new[] { option, new PlateOption { Width = 12, Length = 12 } }));
+    }
+}

OpenNest.Engine/CuttingPlanning/BestEffortCuttingPlan.cs

@@ -0,0 +1,92 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using OpenNest.CNC.CuttingPlanning;
+using OpenNest.Diagnostics;
+
+namespace OpenNest.Engine.CuttingPlanning;
+
+/// <summary>
+/// A deliberately uncertified fallback, not a relaxed safety checker. Reuses closed native
+/// contour preparation and emission, retaining source order except for proven prerequisites.
+/// Unknown program semantics, invalid motions and unrepresentable contours still refuse.
+/// </summary>
+internal static class BestEffortCuttingPlan
+{
+    internal static CuttingPlanResult Plan(CuttingPlanSnapshot snapshot, CancellationToken token)
+    {
+        if (snapshot.Failure is { } failure)
+            return new(failure, findings: snapshot.Findings);
+        if (!snapshot.Regeneration || snapshot.OwnedParameters == null)
+            return new(CuttingPlanStatus.InvalidInput);
+        var findings = snapshot.Findings.ToList();
+        findings.Add(new(null, null, null, null, PostVerificationKind.Incomplete,
+            "Best-effort plan: lead clearance, rapid travel and material containment are not certified. "
+            + "Review the complete plan before cutting. Source contours have not been repaired."));
+        var order = new List<FixedProgramPlacement>();
+        var done = new HashSet<int>();
+        var position = snapshot.StartPoint;
+        var distance = 0.0;
+        var checker = new ReleasedContourState(reportMissingLeadIns: false);
+        try
+        {
+            while (order.Count < snapshot.Placements.Count)
+            {
+                token.ThrowIfCancellationRequested();
+                var source = snapshot.PreservePartOrder ? snapshot.Placements[order.Count]
+                    : snapshot.Placements.FirstOrDefault(p => !done.Contains(p.SourceOrdinal)
+                        && snapshot.Dependencies.IsReady(p.SourceOrdinal, done));
+                if (source == null || !snapshot.Dependencies.IsReady(source.SourceOrdinal, done))
+                    return new(CuttingPlanStatus.ConstraintConflict, findings: findings);
+                var proposal = source;
+                if (source.Prepared is { } prepared)
+                {
+                    var choices = new List<ContourChoice>();
+                    var approach = position - source.Location;
+                    for (var contour = 0; contour < prepared.Count; contour++)
+                    {
+                        token.ThrowIfCancellationRequested();
+                        choices.Add(prepared.ClosestEntry(contour, approach));
+                        // Prefixes are standalone programs, not relative to the prior prefix.
+                        var prefix = ExecutionMotionReader.ReadSupported(prepared.EmitPrefix(choices),
+                            source.Location, position, token);
+                        approach = prefix.DeparturePoint - source.Location;
+                    }
+                    var program = prepared.Emit(choices);
+                    var emitted = ExecutionMotionReader.ReadSupported(program, source.Location, position, token);
+                    proposal = source.Propose(program, emitted, choices, token);
+                }
+                // Read the owned payload again; malformed/nonfinite output never reaches Apply.
+                var execution = ExecutionMotionReader.ReadSupported(proposal.CopyProgram(), source.Location, position, token);
+                if (!execution.HasCuttingContour)
+                    throw new ArgumentException("Best-effort output has no cutting contour.");
+                findings.AddRange(checker.Check(execution, position, source.SourceOrdinal + 1, source.IsCutOff, token)
+                    .Select(f => new CuttingPlanFinding(f.PartNumber is int part ? part - 1 : null,
+                        f.PartNumber is int ordinal ? snapshot.Placements[ordinal - 1].SourcePart : null,
+                        f.OtherPartNumber is int other ? other - 1 : null,
+                        f.OtherPartNumber is int otherOrdinal ? snapshot.Placements[otherOrdinal - 1].SourcePart : null,
+                        f.Kind, f.Message)));
+                distance += execution.RapidDistanceFrom(position);
+                if (!double.IsFinite(distance))
+                    throw new ArgumentException("Best-effort travel is not finite.");
+                position = execution.DeparturePoint;
+                done.Add(source.SourceOrdinal);
+                order.Add(proposal);
+            }
+            token.ThrowIfCancellationRequested();
+            return new(CuttingPlanStatus.BestEffort, order, findings, rapidDistance: distance)
+            { Snapshot = snapshot };
+        }
+        catch (OperationCanceledException)
+        {
+            return new(CuttingPlanStatus.Cancelled);
+        }
+        catch (Exception exception) when (exception is ArgumentException or NotSupportedException
+            or InvalidOperationException or ArithmeticException)
+        {
+            findings.Add(new(null, null, null, null, PostVerificationKind.Incomplete, exception.Message));
+            return new(CuttingPlanStatus.UnsupportedGeometry, findings: findings);
+        }
+    }
+}

OpenNest.Engine/CuttingPlanning/ContourEntryFeasibility.cs

@@ -31,8 +31,8 @@ public sealed record ContourFeasibilityVerdict(ContourFeasibilityStatus Status,
 /// candidate contour through the S06 diagnostic seam, reads it at the placement position,
 /// and certifies the emitted lead-in and lead-out against ALL placed material. It is not a
 /// new collision implementation and not a plan approval: a Clear verdict certifies this
-/// contour's emitted leads only — the missing-lead (NoLeadIn) check still runs later on the
+/// contour's emitted leads only — NoLeadIn is supported, and the complete plan must
-/// complete plan, and rapids/pierce clearance belong to their existing checkers. A
+/// still pass rapid travel and contour-accounting checks. A
 /// candidate rejected here is not proven infeasible by anything else: this adapter only
 /// reports what the validator reported.
 /// One instance is one captured planning attempt: verdicts cache per exact choice and node

OpenNest.Engine/CuttingPlanning/CuttingDependencyGraph.cs

@@ -76,7 +76,7 @@ internal sealed class CuttingDependencyGraph
     }
 
     internal static CuttingDependencyGraph Build(IReadOnlyList<DependencyNode> nodes, Box plate,
-        CancellationToken token)
+        CancellationToken token, Action<CuttingDependencyException> uncertain = null)
     {
         var edges = nodes.Select(_ => new SortedSet<int>()).ToArray();
         for (var cut = 0; cut < nodes.Count; cut++)
@@ -98,10 +98,25 @@ internal sealed class CuttingDependencyGraph
                 token.ThrowIfCancellationRequested();
                 // Bounds only select candidates; containment itself is proven on native material.
                 if (inner != host && !nodes[inner].IsCutOff && !nodes[host].IsCutOff
-                    && Within(nodes[inner].CleanBounds, nodes[host].HostBounds)
+                    && Within(nodes[inner].CleanBounds, nodes[host].HostBounds))
-                    && InsideCutout(nodes, inner, host, token))
+                {
+                    try
+                    {
+                        if (InsideCutout(nodes, inner, host, token))
                             edges[host].Add(inner);
                     }
+                    catch (CuttingDependencyException exception) when (uncertain != null
+                        && exception.Status == CuttingPlanStatus.UnsupportedGeometry)
+                    {
+                        uncertain(exception);
+                    }
+                    catch (Exception exception) when (uncertain != null
+                        && exception is ArgumentException or NotSupportedException)
+                    {
+                        uncertain(Ambiguous(inner, host, exception.Message));
+                    }
+                }
+            }
         var graph = new CuttingDependencyGraph(edges.Select(e => e.ToArray()).ToArray());
         if (graph.FindCycle() is { } cyclic)
             throw new CuttingDependencyException(CuttingPlanStatus.ConstraintConflict, cyclic, null,

OpenNest.Engine/CuttingPlanning/CuttingPlanBatch.cs

@@ -43,6 +43,10 @@ public sealed class CuttingPlanBatch
     /// </summary>
     public const int ExpansionsPerPart = 400;
 
+    // Extra bounded work on hard/refused plates; the full-cap search still gets its whole budget.
+    internal const int FirstPassBudget = 1000;
+    internal const int FirstPassEntries = 8;
+
     private readonly Entry[] entries;
     private readonly CuttingParameters ownedParameters;
 
@@ -99,7 +103,11 @@ public sealed class CuttingPlanBatch
             var reorder = preservePartOrder ? null : CuttingPlanService.Capture(CuttingPlanRequest.ForPlate(plate,
                 expansionBudget: reorderBudget ?? budget, confirmedParameters: confirmedParameters), token);
             var overlap = PlateOverlapAnalyzer.Capture(plate.Parts.ToArray(), token);
-            entries[index] = new(plate, plateNumbers?[index] ?? index + 1, reorder, keepOrder, overlap);
+            var fallback = reorder ?? keepOrder;
+            if (fallback.Failure == CuttingPlanStatus.UnsupportedGeometry)
+                fallback = CuttingPlanService.Capture(CuttingPlanRequest.ForPlate(plate,
+                    confirmedParameters: confirmedParameters, preservePartOrder: preservePartOrder), token, bestEffort: true);
+            entries[index] = new(plate, plateNumbers?[index] ?? index + 1, reorder, keepOrder, overlap, fallback);
         }
         return new(entries, owned);
     }
@@ -112,7 +120,8 @@ public sealed class CuttingPlanBatch
     /// Checks and plans every plate from its captured snapshots. Safe on a worker: live plates are
     /// not read. Overlapping material blocks a plate whatever its route. A free search that ends
     /// without a complete plan within its budget is retried with the current order; the proposal
-    /// reports that it kept the order.
+    /// reports that it kept the order. Incomplete geometry also gets a separately labelled,
+    /// unverified fallback when supported closed contours can still be emitted.
     /// </summary>
     public CuttingPlanProposal Plan(IProgress<CuttingPlanProgress> progress = null,
         CancellationToken token = default)
@@ -137,22 +146,50 @@ public sealed class CuttingPlanBatch
             if (entry.Reorder != null)
             {
                 progress?.Report(new(index, entries.Length, entry.Number, CuttingPlanPhase.Reordering));
-                reorder = CuttingPlanService.Plan(entry.Reorder, token);
+                reorder = PlanReorder(entry.Reorder, token);
                 if (reorder.Status != CuttingPlanStatus.NoSolutionWithinBudget)
                 {
-                    plans[index] = new(entry.Plate, entry.Number, reorder, null, overlap);
+                    plans[index] = new(entry.Plate, entry.Number, WithFallback(entry, reorder, token), null, overlap);
                     continue;
                 }
             }
             progress?.Report(new(index, entries.Length, entry.Number, CuttingPlanPhase.KeepingOrder));
-            plans[index] = new(entry.Plate, entry.Number, CuttingPlanService.Plan(entry.KeepOrder, token), reorder,
+            plans[index] = new(entry.Plate, entry.Number,
-                overlap);
+                WithFallback(entry, CuttingPlanService.Plan(entry.KeepOrder, token), token), reorder, overlap);
         }
         return new(plans, ownedParameters);
     }
 
+    internal static CuttingPlanResult PlanReorder(CuttingPlanSnapshot snapshot, CancellationToken token,
+        int firstPassBudget = FirstPassBudget)
+    {
+        // A failed first pass is not a proof of impossibility: retain all original
+        // full-cap alternatives and the complete original budget for the retry.
+        if (snapshot.Failure == null && snapshot.Regeneration && snapshot.MaxEntries > FirstPassEntries
+            && snapshot.ExpansionBudget > firstPassBudget)
+        {
+            var first = CuttingPlanService.Plan(snapshot.WithSearchLimits(firstPassBudget, FirstPassEntries), token);
+            if ((first.Status == CuttingPlanStatus.Ready && first.IndependentlyReplayed)
+                || first.Status == CuttingPlanStatus.Cancelled)
+                return first;
+        }
+        return CuttingPlanService.Plan(snapshot, token);
+    }
+
+    private static CuttingPlanResult WithFallback(Entry entry, CuttingPlanResult strict, CancellationToken token)
+    {
+        if (strict.Status != CuttingPlanStatus.UnsupportedGeometry || entry.Fallback.Failure != null)
+            return strict;
+        var fallback = BestEffortCuttingPlan.Plan(entry.Fallback, token);
+        if (fallback.Status != CuttingPlanStatus.BestEffort)
+            return fallback.Status == CuttingPlanStatus.Cancelled ? fallback : strict;
+        return new(CuttingPlanStatus.BestEffort, fallback.ProposedOrder,
+            strict.Findings.Concat(fallback.Findings).Distinct(), rapidDistance: fallback.RapidDistance)
+        { Snapshot = entry.Fallback };
+    }
+
     private sealed record Entry(Plate Plate, int Number, CuttingPlanSnapshot Reorder, CuttingPlanSnapshot KeepOrder,
-        PlateOverlapSnapshot Overlap);
+        PlateOverlapSnapshot Overlap, CuttingPlanSnapshot Fallback);
 }
 
 /// <summary>One plate's outcome inside a <see cref="CuttingPlanProposal"/>.</summary>
@@ -188,6 +225,10 @@ public sealed class CuttingPlanPlateResult
 
     public bool IsOverlapClear => Overlap is { IsComplete: true } && Overlap.Pairs.Count == 0;
     public bool IsReady => IsRouteReady && IsOverlapClear;
+
+    /// <summary>Owned readable output is available, but not all geometric checks passed.</summary>
+    public bool CanApplyWithWarnings => Overlap != null && Overlap.Pairs.Count == 0
+        && (IsRouteReady || Result.Status == CuttingPlanStatus.BestEffort);
     public int PartCount => Result.ProposedOrder.Count;
     public int RegeneratedCount => Result.ProposedOrder.Count(p => p.IsRegenerated);
 
@@ -195,8 +236,12 @@ public sealed class CuttingPlanPlateResult
         Result.ProposedOrder.Select((proposal, index) => proposal.SourceOrdinal != index).Any(changed => changed);
 }
 
+/// <summary>A diagnostic tied to captured plate and source part positions, not display text.</summary>
+public sealed record CuttingPlanDiagnosticRow(int PlateIndex, int PlateNumber, int? PartNumber,
+    int? OtherPartNumber, string Message);
+
 /// <summary>
-/// The outcome of a batch. Apply is all-or-nothing and is offered only when every plate is ready.
+/// The outcome of a batch. Apply is all-or-nothing. Unverified output needs explicit acceptance.
 /// </summary>
 public sealed class CuttingPlanProposal
 {
@@ -216,17 +261,55 @@ public sealed class CuttingPlanProposal
     public bool CanApply => Plates.Count > 0 && !IsCancelled && ownedParameters != null
         && Plates.All(p => p.IsReady);
 
+    /// <summary>All plates have usable output, possibly requiring explicit warning acceptance.</summary>
+    public bool CanApplyWithWarnings => Plates.Count > 0 && !IsCancelled && ownedParameters != null
+        && Plates.All(p => p.CanApplyWithWarnings);
+
+    public bool RequiresWarningAcceptance => CanApplyWithWarnings && !CanApply;
+
+    /// <summary>All findings, including ones hidden by a blocked plate's abbreviated summary.</summary>
+    public IReadOnlyList<CuttingPlanDiagnosticRow> DiagnosticRows()
+    {
+        var rows = new List<CuttingPlanDiagnosticRow>();
+        for (var index = 0; index < Plates.Count; index++)
+        {
+            var plate = Plates[index];
+            if (plate.Overlap != null)
+            {
+                foreach (var pair in plate.Overlap.Pairs)
+                    rows.Add(new(index, plate.PlateNumber, pair.PartAId + 1, pair.PartBId + 1,
+                        $"Part {pair.PartAId + 1}{Name(pair.PartAName)} overlaps part "
+                        + $"{pair.PartBId + 1}{Name(pair.PartBName)}."));
+                foreach (var issue in plate.Overlap.Issues)
+                    rows.Add(new(index, plate.PlateNumber, issue.PartAId + 1,
+                        issue.PartBId is int other ? other + 1 : null,
+                        $"Overlap check incomplete for part {issue.PartAId + 1}"
+                        + (issue.PartBId is int second ? $" and part {second + 1}" : string.Empty)
+                        + $": {issue.Message}"));
+            }
+            foreach (var finding in plate.Result.Findings)
+                rows.Add(new(index, plate.PlateNumber,
+                    finding.SourceOrdinal is int part ? part + 1 : null,
+                    finding.OtherSourceOrdinal is int other ? other + 1 : null,
+                    DescribeFinding(finding)));
+        }
+        return rows;
+    }
+
     /// <summary>
     /// Installs every plate's replayed proposal through <see cref="CuttingPlanService.Apply"/>, on the
     /// thread that owns the plates. Only after every plate is applied does each one keep an owned copy
     /// of the confirmed parameters as its cutting settings; any other status changes nothing.
     /// </summary>
-    public CuttingCommitResult Apply(CancellationToken token = default)
+    public CuttingCommitResult Apply(CancellationToken token = default) => Apply(false, token);
+
+    /// <summary>Explicit per-proposal acceptance; never grants consent to post CNC output.</summary>
+    public CuttingCommitResult Apply(bool acceptWarnings, CancellationToken token = default)
     {
-        if (!CanApply)
+        if (!(CanApply || acceptWarnings && CanApplyWithWarnings))
             return new(CuttingCommitStatus.InvalidInput,
                 "Every plate must have a ready plan before anything is applied.");
-        var commit = CuttingPlanService.Apply(Plates.Select(p => p.Result), token);
+        var commit = CuttingPlanService.Apply(Plates.Select(p => p.Result), token, null, acceptWarnings);
         if (commit.Status == CuttingCommitStatus.Applied)
             foreach (var plate in Plates)
                 plate.Plate.CuttingParameters = OwnedCuttingParameters.Copy(ownedParameters);
@@ -234,18 +317,17 @@ public sealed class CuttingPlanProposal
     }
 
     /// <summary>
-    /// A detached copy of a ready plate for display, in the proposed order with the proposed
+    /// A detached copy of a ready or explicitly unverified proposal for display, or null.
-    /// programs, or null. A refused plate is not previewed: its program graphs may be unsafe to
+    /// Refused graphs are never cloned. Changed plates are not previewed at uncaptured poses.
-    /// copy. Neither is a plate that changed after planning, which would draw replayed programs at
+    /// The copy has quantity zero, so drawing quantities stay put.
-    /// poses that were never checked. The copy has quantity zero, so drawing quantities stay put.
     /// Call it on the thread that owns the plates.
     /// </summary>
     public Plate BuildPreview(int index)
     {
         var planned = Plates[index];
-        if (!planned.IsReady || planned.Result.Snapshot?.PlateState?.IsCurrent() != true)
+        if (!planned.CanApplyWithWarnings || planned.Result.Snapshot?.PlateState?.IsCurrent() != true)
             return null;
-        // Unchanged since capture: live poses, plate and programs are the validated, replayed ones.
+        // Unchanged since capture: graphs are supported and the preview uses the exact proposal.
         var source = planned.Plate;
         var preview = new Plate(source.Size)
         {
@@ -267,15 +349,18 @@ public sealed class CuttingPlanProposal
     public IReadOnlyList<string> Describe(string unit)
     {
         var lines = new List<string>();
-        var ready = Plates.Count(p => p.IsReady);
+        var blocked = Plates.Count(p => !p.CanApplyWithWarnings);
         if (IsCancelled)
             lines.Add("Planning was cancelled. Nothing has changed.");
         else if (CanApply)
             lines.Add($"Ready to apply to {Count(Plates.Count, "plate")}: "
                 + $"{Count(Plates.Count(p => p.OrderChanged), "plate")} with a new part order, "
                 + $"{Count(Plates.Sum(p => p.RegeneratedCount), "part program")} regenerated.");
+        else if (RequiresWarningAcceptance)
+            lines.Add("Best-effort plan available. Review the warnings and accept the unverified plan to apply. "
+                + "This is not approval to cut or post CNC output.");
         else
-            lines.Add($"Apply is unavailable: {Plates.Count - ready} of {Count(Plates.Count, "plate")} could not "
+            lines.Add($"Apply is unavailable: {blocked} of {Count(Plates.Count, "plate")} could not "
                 + "be planned. No plate changes until every plate is ready.");
 
         foreach (var plate in Plates)
@@ -307,6 +392,17 @@ public sealed class CuttingPlanProposal
             yield break;
         }
 
+        if (plate.CanApplyWithWarnings)
+        {
+            yield return heading + $"best-effort, unverified. {Count(plate.PartCount, "part")}, "
+                + $"{plate.RegeneratedCount} regenerated; review lead-ins and cutting order.";
+            // Unverified Apply requires the operator to see every finding, not just a
+            // bounded diagnostic summary that hides later parts behind "... and N more".
+            foreach (var line in DescribeOverlap(plate.Overlap).Concat(result.Findings.Select(DescribeFinding)))
+                yield return "  - " + line;
+            yield break;
+        }
+
         var missingLead = !plate.IsRouteReady && result.Status != CuttingPlanStatus.Cancelled
             && result.Findings.Any(f => f.Kind == PostVerificationKind.MissingLeadIn);
         yield return heading + (plate.IsRouteReady

OpenNest.Engine/CuttingPlanning/CuttingPlanModels.cs

@@ -60,8 +60,9 @@ public sealed class CuttingPlanSnapshot
         int expansionBudget, CuttingPlanStatus? failure = null, IEnumerable<CuttingPlanFinding> findings = null,
         bool regeneration = false, bool preservePartOrder = false, int maxEntries = 16,
         Action<int> expansionObserver = null, PlateCuttingState plateState = null,
-        CuttingParameters ownedParameters = null, CuttingDependencyGraph dependencies = null)
+        CuttingParameters ownedParameters = null, CuttingDependencyGraph dependencies = null, bool bestEffort = false)
     {
+        BestEffort = bestEffort;
         PlateState = plateState;
         OwnedParameters = ownedParameters;
         Placements = Array.AsReadOnly(placements.ToArray());
@@ -82,6 +83,7 @@ public sealed class CuttingPlanSnapshot
     internal PlateCuttingState PlateState { get; }
     /// <summary>Owned copy of the confirmed parameters taken at capture; never the caller's object.</summary>
     internal CuttingParameters OwnedParameters { get; }
+    internal bool BestEffort { get; }
     internal bool Regeneration { get; }
     internal bool PreservePartOrder { get; }
     internal int MaxEntries { get; }
@@ -91,6 +93,13 @@ public sealed class CuttingPlanSnapshot
     public int ExpansionBudget { get; }
     internal CuttingPlanStatus? Failure { get; }
     internal IReadOnlyList<CuttingPlanFinding> Findings { get; }
+
+    // A worker-only search variant over the same owned capture. Never recapture the live plate:
+    // both proposals retain the identical freshness record and confirmed settings.
+    internal CuttingPlanSnapshot WithSearchLimits(int expansionBudget, int maxEntries) =>
+        new(Placements, StartPoint, expansionBudget, Failure, Findings, Regeneration,
+            PreservePartOrder, maxEntries, ExpansionObserver, PlateState, OwnedParameters,
+            Dependencies, BestEffort);
 }
 
 public sealed class FixedProgramPlacement
@@ -159,7 +168,9 @@ public enum CuttingPlanStatus
     UnsupportedGeometry,
     InvalidInput,
     NoSolutionWithinBudget,
-    Cancelled
+    Cancelled,
+    /// <summary>Usable owned programs, but geometric safety checks did not pass. Never Ready.</summary>
+    BestEffort
 }
 
 /// <summary>Ordinals are zero-based source positions, not proposed sequence positions.</summary>
@@ -169,7 +180,8 @@ public sealed record CuttingPlanFinding(int? SourceOrdinal, Part SourcePart,
 /// <summary>
 /// A replayed direct-XY proposal, optionally with regenerated programs, that respects the
 /// captured cutoff/containment prerequisites. Not physical safety or posting consent. Apply
-/// installs it only for a plate-scoped request whose plate is unchanged. Failures contain no proposals.
+/// installs it only for a plate-scoped request whose plate is unchanged. BestEffort is explicitly
+/// unverified and requires batch warning acceptance; other failures contain no proposals.
 /// </summary>
 public sealed class CuttingPlanResult
 {

OpenNest.Engine/CuttingPlanning/CuttingPlanService.cs

@@ -15,9 +15,13 @@ public static class CuttingPlanService
     /// Read stable caller-owned sources once into privately owned programs and geometry.
     /// No private Plates, settings aliases, quantity updates or source subcall rebinding.
     /// </summary>
-    public static CuttingPlanSnapshot Capture(CuttingPlanRequest request, CancellationToken token = default)
+    public static CuttingPlanSnapshot Capture(CuttingPlanRequest request, CancellationToken token = default) =>
+        Capture(request, token, bestEffort: false);
+
+    internal static CuttingPlanSnapshot Capture(CuttingPlanRequest request, CancellationToken token, bool bestEffort)
     {
         var placements = new List<FixedProgramPlacement>();
+        var warnings = new List<CuttingPlanFinding>();
         Part source = null;
         int? ordinal = null;
         try
@@ -107,7 +111,11 @@ public static class CuttingPlanService
                 {
                     material = LeadMaterialSnapshot.Capture(ownedClean, location, token);
                     if (!material.IsComplete)
+                    {
+                        if (!bestEffort)
                             throw new NotSupportedException(material.Reason);
+                        warnings.Add(new(index, source, null, null, PostVerificationKind.Incomplete, material.Reason));
+                    }
                     if (!source.LeadInsLocked && (request.EligibleParts == null || eligible.Contains(source)))
                         prepared = PreparedContours.Capture(ownedClean, request.ConfirmedParameters, token);
                 }
@@ -122,13 +130,16 @@ public static class CuttingPlanService
             placements[0].Execution.RapidDistanceFrom(request.StartPoint);
             source = null;
             ordinal = null;
-            var dependencies = CuttingDependencyGraph.Build(nodes, request.Plate?.BoundingBox(includeParts: false), token);
+            var dependencies = CuttingDependencyGraph.Build(nodes, request.Plate?.BoundingBox(includeParts: false), token,
+                bestEffort ? exception => warnings.Add(new(exception.Ordinal, request.Parts[exception.Ordinal],
+                    exception.Other, exception.Other is int other ? request.Parts[other] : null,
+                    PostVerificationKind.Incomplete, exception.Message)) : null);
             return new(placements, request.StartPoint, request.ExpansionBudget, regeneration: request.ConfirmedParameters != null,
                 preservePartOrder: request.PreservePartOrder, maxEntries: request.MaxEntries,
                 expansionObserver: request.ExpansionObserver, plateState: plateState,
                 ownedParameters: request.ConfirmedParameters == null ? null
                     : OwnedCuttingParameters.Copy(request.ConfirmedParameters),
-                dependencies: dependencies);
+                dependencies: dependencies, findings: warnings, bestEffort: bestEffort);
         }
         catch (OperationCanceledException)
         {
@@ -175,14 +186,15 @@ public static class CuttingPlanService
 
     // beforeInstall is the commit's install-boundary test seam.
     internal static CuttingCommitResult Apply(IEnumerable<CuttingPlanResult> results, CancellationToken token,
-        Action<Plate, Part> beforeInstall)
+        Action<Plate, Part> beforeInstall, bool acceptUnverified = false)
     {
         var plans = new List<PlateCuttingPlan>();
         foreach (var result in results ?? [])
         {
             var snapshot = result?.Snapshot;
-            if (result?.Status != CuttingPlanStatus.Ready || !result.IndependentlyReplayed
+            var eligible = result != null && (result.Status == CuttingPlanStatus.Ready && result.IndependentlyReplayed
-                || snapshot?.PlateState == null || result.ProposedOrder.Count != snapshot.Placements.Count)
+                || acceptUnverified && result.Status == CuttingPlanStatus.BestEffort);
+            if (!eligible || snapshot?.PlateState == null || result.ProposedOrder.Count != snapshot.Placements.Count)
                 return new(CuttingCommitStatus.InvalidInput,
                     "Only Ready, independently replayed plate-scoped proposals can be applied.");
             var programs = new List<PlannedPartProgram>();
@@ -211,6 +223,8 @@ public static class CuttingPlanService
             return new(CuttingPlanStatus.InvalidInput);
         if (snapshot.Failure is { } failure)
             return new(failure, findings: snapshot.Findings);
+        if (snapshot.BestEffort)
+            return BestEffortCuttingPlan.Plan(snapshot, token);
         if (snapshot.Placements.Count == 0)
             return snapshot.PlateState == null ? new(CuttingPlanStatus.InvalidInput)
                 : new(CuttingPlanStatus.Ready, independentlyReplayed: true); // Empty plate: unchanged no-op.
@@ -227,7 +241,7 @@ public static class CuttingPlanService
                 if (placement.Prepared != null)
                     continue; // An eligible old crossing is precisely what regeneration may repair.
                 // Ignore only the unknown incoming rapid. Every fixed internal motion is checked.
-                var findings = new ReleasedContourState().Check(placement.Execution, null,
+                var findings = new ReleasedContourState(reportMissingLeadIns: false).Check(placement.Execution, null,
                     placement.SourceOrdinal + 1, placement.IsCutOff, token);
                 fixedFindings.AddRange(Map(snapshot, findings));
             }
@@ -265,7 +279,7 @@ public static class CuttingPlanService
         if (snapshot.Dependencies.FirstViolation(order) is { } violation)
             return new(CuttingPlanStatus.InvalidInput,
                 findings: [DependencyFinding(snapshot, violation, "The proposed order")], expansions: expansions);
-        var checker = new ReleasedContourState();
+        var checker = new ReleasedContourState(reportMissingLeadIns: false);
         var position = snapshot.StartPoint;
         var distance = 0.0;
         var findings = new List<PostVerificationFinding>();
@@ -299,7 +313,7 @@ public static class CuttingPlanService
         if (snapshot.Dependencies.FirstViolation(order.Select(p => p.SourceOrdinal).ToArray()) is { } violation)
             return new(CuttingPlanStatus.InvalidInput,
                 findings: [DependencyFinding(snapshot, violation, "The proposed order")], expansions: expansions);
-        var checker = new ReleasedContourState();
+        var checker = new ReleasedContourState(reportMissingLeadIns: false);
         var position = snapshot.StartPoint;
         var distance = 0.0;
         var findings = new List<CuttingPlanFinding>();

OpenNest.Engine/CuttingPlanning/FixedProgramSearch.cs

@@ -16,7 +16,7 @@ internal static class FixedProgramSearch
     internal static Outcome Run(CuttingPlanSnapshot snapshot, CancellationToken token)
     {
         var stack = new Stack<Frame>();
-        stack.Push(Create([], snapshot.StartPoint, new ReleasedContourState()));
+        stack.Push(Create([], snapshot.StartPoint, new ReleasedContourState(reportMissingLeadIns: false)));
         var rejected = new HashSet<PostVerificationFinding>();
         var expansions = 0;
         while (stack.Count != 0)

OpenNest.Engine/CuttingPlanning/JointCuttingPlanSearch.cs

@@ -191,11 +191,13 @@ internal static class JointCuttingPlanSearch
         /// </summary>
         internal Attempt Follow(int[] sequence, int? stall, Node resume, bool preferredOnly = false)
         {
-            var root = resume ?? new Node([], snapshot.StartPoint, new ReleasedContourState(), null, null);
+            var root = resume ?? new Node([], snapshot.StartPoint, new ReleasedContourState(reportMissingLeadIns: false), null, null);
             var attempt = new Attempt(sequence);
             var progressExpansions = Expansions;
             var stack = new Stack<Frame>();
             stack.Push(new(root));
+            try
+            {
                 while (stack.Count != 0)
                 {
                     token.ThrowIfCancellationRequested();
@@ -210,16 +212,24 @@ internal static class JointCuttingPlanSearch
                         progressExpansions = Expansions;
                     else if (stall is int limit && Expansions - progressExpansions > limit)
                         return attempt;
-                frame.Children ??= OrderedChildren(node, sequence, attempt, preferredOnly);
+                    frame.Children ??= OrderedChildren(node, sequence, attempt, preferredOnly).GetEnumerator();
-                if (frame.Next == frame.Children.Length)
+                    if (!frame.Children.MoveNext())
                     {
-                    stack.Pop();
+                        stack.Pop().Children.Dispose();
                         continue;
                     }
-                stack.Push(new(frame.Children[frame.Next++].Node));
+                    stack.Push(new(frame.Children.Current.Node));
                 }
                 return attempt;
             }
+            finally
+            {
+                // Ready, stalled, cancelled and budget-exhausted searches can all leave
+                // suspended siblings. Release their captured prefixes on every exit.
+                foreach (var frame in stack)
+                    frame.Children?.Dispose();
+            }
+        }
 
         /// <summary>
         /// The NEXT cut's centre that the outside entry should face, or null for the last
@@ -259,8 +269,14 @@ internal static class JointCuttingPlanSearch
         /// one part and contour stage the automatic rank leads — OrderBy(Distance) alone
         /// would undo the look-ahead facing. Legacy (unranked) children keep distance order.
         /// </summary>
-        private Edge[] OrderedChildren(Node node, int[] sequence, Attempt attempt, bool preferredOnly)
+        private IEnumerable<Edge> OrderedChildren(Node node, int[] sequence, Attempt attempt, bool preferredOnly)
         {
+            // A prescribed next part (or an active part's next contour) has a single
+            // source. Expand already yields its contour/entry rank order, so emit and
+            // validate a sibling only when DFS reaches it. Free whole-part selection
+            // still needs every source's distances before it can rank them.
+            if (sequence != null || node.Active != null)
+                return Expand(node, sequence, attempt, preferredOnly);
             var edges = Expand(node, sequence, attempt, preferredOnly).ToList();
             if (edges.Count <= 1)
                 return edges.ToArray();
@@ -334,8 +350,10 @@ internal static class JointCuttingPlanSearch
                 // First try one ranked hole chain per endpoint. A later-part failure then
                 // changes the endpoint before replaying all earlier hole combinations.
                 // The retained pass below still searches every entry and hole order.
+                if (preference != null)
+                    contours = contours.OrderBy(c => Array.IndexOf(preference.Route, c)).ThenBy(c => c);
                 if (preferredOnly && preference != null)
-                    contours = contours.OrderBy(c => Array.IndexOf(preference.Route, c)).Take(1);
+                    contours = contours.Take(1);
                 foreach (var contour in contours)
                 {
                     token.ThrowIfCancellationRequested();
@@ -593,7 +611,6 @@ internal static class JointCuttingPlanSearch
     private sealed class Frame(Node node)
     {
         internal Node Node { get; } = node;
-        internal Edge[] Children { get; set; }
+        internal IEnumerator<Edge> Children { get; set; }
-        internal int Next { get; set; }
     }
 }

OpenNest.Engine/Fill/Compactor.cs

@@ -290,6 +290,63 @@ namespace OpenNest.Engine.Fill
             return 0;
         }
 
+        /// <summary>
+        /// Settles a copied placement against the plate in both axis orders, choosing
+        /// the group closest to the quadrant's work-area corner. A coarse box pass
+        /// runs only when no moving box starts inside an existing part's box.
+        /// </summary>
+        public static void SettlePlacement(
+            List<Part> movingParts,
+            Plate plate,
+            PushDirection horizontal,
+            PushDirection vertical,
+            int maxIterations = 20
+        )
+        {
+            if (movingParts.Count == 0)
+                return;
+
+            var workArea = plate.WorkArea();
+            var skipBoxes = movingParts.Any(moving =>
+                plate.Parts.Any(obstacle => moving.BoundingBox.Intersects(obstacle.BoundingBox))
+            );
+            var bestScore = double.MaxValue;
+            Vector[] best = null;
+
+            foreach (var first in new[] { horizontal, vertical })
+            {
+                var second = first == horizontal ? vertical : horizontal;
+                var trial = movingParts.Select(p => (Part)p.Clone()).ToList();
+                if (!skipBoxes)
+                {
+                    PushBoundingBox(trial, plate, first);
+                    PushBoundingBox(trial, plate, second);
+                }
+
+                for (var i = 0; i < maxIterations; i++)
+                {
+                    var moved = Push(trial, plate, first) + Push(trial, plate, second);
+                    if (moved < 0.01)
+                        break;
+                }
+
+                var bounds = trial.GetBoundingBox();
+                var dx = horizontal == PushDirection.Left
+                    ? bounds.Left - workArea.Left : workArea.Right - bounds.Right;
+                var dy = vertical == PushDirection.Down
+                    ? bounds.Bottom - workArea.Bottom : workArea.Top - bounds.Top;
+                var score = dx * dx + dy * dy;
+                if (score < bestScore)
+                {
+                    bestScore = score;
+                    best = trial.Select(p => p.Location).ToArray();
+                }
+            }
+
+            for (var i = 0; i < movingParts.Count; i++)
+                movingParts[i].Location = best[i];
+        }
+
         /// <summary>
         /// Repeatedly pushes parts left then down until total movement per
         /// iteration falls below the given threshold.

OpenNest.Engine/Jobs/Cutouts/CutoutLatticeFill.cs

@@ -22,20 +22,24 @@ namespace OpenNest.Engine.Jobs.Cutouts;
 /// </summary>
 /// <remarks>
 /// Suited to many small copies in a large cutout; a few large inserts belong to NFP placement.
-/// Poses are in the frame's own coordinates: frame at the origin, unrotated. Not wired into
+/// Poses are in the frame's own coordinates: frame at the origin, unrotated. Used by the
-/// any engine or pipeline yet: placing parts in cutouts waits on containment-aware cutting order.
+/// internal pipeline cutout preview, but not enabled for normal whole-job calls;
+/// production placement waits on cutting/post safety.
 /// </remarks>
 internal static class CutoutLatticeFill
 {
     /// <summary>Offsets tried per side on each axis; the search covers (2n + 1)^2 offsets.</summary>
     internal const int DefaultShiftSteps = 8;
 
-    private const double FlattenTolerance = 0.001;
+    internal const double FlattenTolerance = 0.001;
 
     /// <summary>Extra growth beyond the spacing, covering flattening and Clipper rounding.</summary>
     private const double Margin = FlattenTolerance + 0.001;
 
     private const int Precision = NestTolerances.ClipperPrecision;
+    // Fill materializes an entire grid before quantity trimming. Bound work even for a
+    // tiny insert with demand of only three, rather than allocating millions of clones.
+    private const int MaxLatticePositions = 1000;
 
     /// <summary>Returns up to <paramref name="maxQuantity"/> insert poses inside the cutout,
     /// or none when no copy fits.</summary>
@@ -45,9 +49,17 @@ internal static class CutoutLatticeFill
 
     internal static IReadOnlyList<NestJobPlacement> Fill(NestJobPart frame, int cutoutIndex,
         NestJobPart insert, int maxQuantity, double spacing, int shiftSteps, CancellationToken token)
+        => Fill(frame, cutoutIndex, insert, maxQuantity, spacing, shiftSteps,
+            Array.Empty<(JobPartGeometry Geometry, NestJobPlacement Pose)>(), token);
+
+    internal static IReadOnlyList<NestJobPlacement> Fill(NestJobPart frame, int cutoutIndex,
+        NestJobPart insert, int maxQuantity, double spacing, int shiftSteps,
+        IReadOnlyList<(JobPartGeometry Geometry, NestJobPlacement Pose)> occupied, CancellationToken token)
     {
         ArgumentNullException.ThrowIfNull(frame);
         ArgumentNullException.ThrowIfNull(insert);
+        ArgumentNullException.ThrowIfNull(occupied);
+        token.ThrowIfCancellationRequested();
         ArgumentOutOfRangeException.ThrowIfNegative(shiftSteps);
         if (maxQuantity <= 0 || !double.IsFinite(spacing) || spacing < 0)
             return Array.Empty<NestJobPlacement>();
@@ -69,6 +81,10 @@ internal static class CutoutLatticeFill
         var bounds = cutout.BoundingBox;
         var insertBounds = insertGeometry.Bounds;
         var step = System.Math.Max(insertBounds.Length, insertBounds.Width) + spacing;
+        var estimated = (System.Math.Ceiling(bounds.Length / step) + 4)
+            * (System.Math.Ceiling(bounds.Width / step) + 4);
+        if (!(step > 0) || !double.IsFinite(estimated) || estimated > MaxLatticePositions)
+            return Array.Empty<NestJobPlacement>();
 
         var lattice = Lattice(insert, bounds, step, spacing, token);
         if (lattice.Count == 0)
@@ -83,7 +99,8 @@ internal static class CutoutLatticeFill
             {
                 token.ThrowIfCancellationRequested();
                 var (dx, dy) = Shift(step, shiftSteps, i, j);
-                var count = lattice.Count(p => Inside(regions[p.Rotation], p.X + dx, p.Y + dy));
+                var count = lattice.Count(p => Inside(regions[p.Rotation], p.X + dx, p.Y + dy)
+                    && ClearsOccupied(p, dx, dy));
                 if (Better(count, i, j, best))
                     best = (count, i, j);
             }
@@ -91,13 +108,33 @@ internal static class CutoutLatticeFill
             return Array.Empty<NestJobPlacement>();
 
         var (sx, sy) = Shift(step, shiftSteps, best.I, best.J);
-        var kept = lattice.Where(p => Inside(regions[p.Rotation], p.X + sx, p.Y + sy))
+        var kept = lattice.Where(p => Inside(regions[p.Rotation], p.X + sx, p.Y + sy)
+                && ClearsOccupied(p, sx, sy))
             .Select(p => new NestJobPlacement(insert.Id, 0, System.Math.Round(p.X + sx, 8),
                 System.Math.Round(p.Y + sy, 8), p.Rotation))
             .OrderBy(p => p.Y).ThenBy(p => p.X).ThenBy(p => p.Rotation)
             .ToList();
         return Certify(frame.Id, frameGeometry, insertGeometry, kept, spacing, token).Take(maxQuantity)
             .Select((p, index) => p with { InstanceIndex = index }).ToArray();
+
+        bool ClearsOccupied(NestJobPlacement pose, double dx, double dy)
+        {
+            token.ThrowIfCancellationRequested();
+            if (occupied.Count == 0)
+                return true;
+            var moved = pose with
+            {
+                X = System.Math.Round(pose.X + dx, 8),
+                Y = System.Math.Round(pose.Y + dy, 8)
+            };
+            foreach (var other in occupied)
+            {
+                token.ThrowIfCancellationRequested();
+                if (!NestLayoutCheck.Clears(other.Geometry, other.Pose, insertGeometry, moved, spacing))
+                    return false;
+            }
+            return true;
+        }
     }
 
     /// <summary>Fill over the cutout's bounds grown by one step on every side, in frame
@@ -134,7 +171,7 @@ internal static class CutoutLatticeFill
     /// cutout: some point b0 of the grown outline is inside (t in hole - b0) and the grown outline
     /// never meets the cutout boundary (t outside boundary + reflected outline).
     /// </summary>
-    private static PathsD InnerFit(JobPartGeometry insert, double rotation, PathD hole, double spacing)
+    internal static PathsD InnerFit(JobPartGeometry insert, double rotation, PathD hole, double spacing)
     {
         var entities = insert.Perimeter.Entities.Select(e => e.Clone()).ToList();
         foreach (var entity in entities)
@@ -203,7 +240,7 @@ internal static class CutoutLatticeFill
     }
 
     /// <summary>Strictly inside an even-odd region; boundary points count as outside.</summary>
-    private static bool Inside(PathsD region, double x, double y)
+    internal static bool Inside(PathsD region, double x, double y)
     {
         var point = new PointD(x, y);
         var inside = false;
@@ -218,7 +255,7 @@ internal static class CutoutLatticeFill
         return inside;
     }
 
-    private static PathD Positive(PathD path)
+    internal static PathD Positive(PathD path)
     {
         if (path.Count >= 3 && !Clipper.IsPositive(path))
             path.Reverse();

OpenNest.Engine/Jobs/Cutouts/CutoutNfpProposal.cs

@@ -0,0 +1,112 @@
+#nullable enable
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using Clipper2Lib;
+using OpenNest.Geometry;
+
+namespace OpenNest.Engine.Jobs.Cutouts;
+
+/// <summary>Test-only single-insert inner-fit proposal; never changes a job or a live plate.</summary>
+internal static class CutoutNfpProposal
+{
+    // Fixed chord tolerance in the shared round offset otherwise makes extremely large
+    // spacing values allocate an unbounded number of arc vertices. This conservative
+    // test-only kernel declines scales it cannot process safely.
+    private const double MaxCoordinate = 1e8;
+    private const double MaxSpacing = 100;
+
+    /// <summary>Returns one frame-local pose inside a closed cutout, or null if no pose is certified.
+    /// A null result is not a proof that the insert cannot fit elsewhere in this cutout.</summary>
+    internal static NestJobPlacement? Find(NestJobPart frame, int cutoutIndex, NestJobPart insert,
+        double spacing, CancellationToken token = default) =>
+        Find(frame, cutoutIndex, insert, spacing,
+            Array.Empty<(JobPartGeometry Geometry, NestJobPlacement Pose)>(), token);
+
+    /// <summary>Find a pose clearing already accepted inserts as well as the enclosing frame.</summary>
+    internal static NestJobPlacement? Find(NestJobPart frame, int cutoutIndex, NestJobPart insert,
+        double spacing, IReadOnlyList<(JobPartGeometry Geometry, NestJobPlacement Pose)> occupied,
+        CancellationToken token = default)
+    {
+        ArgumentNullException.ThrowIfNull(frame);
+        ArgumentNullException.ThrowIfNull(insert);
+        ArgumentNullException.ThrowIfNull(occupied);
+        token.ThrowIfCancellationRequested();
+        if (!double.IsFinite(spacing) || spacing < 0 || spacing > MaxSpacing)
+            return null;
+        var frameGeometry = JobPartGeometry.TryRead(frame.Geometry);
+        var insertGeometry = JobPartGeometry.TryRead(insert.Geometry);
+        if (frameGeometry == null || insertGeometry == null
+            || !WithinRange(frameGeometry.Bounds) || !WithinRange(insertGeometry.Bounds))
+            return null;
+        ArgumentOutOfRangeException.ThrowIfNegative(cutoutIndex);
+        ArgumentOutOfRangeException.ThrowIfGreaterThanOrEqual(cutoutIndex, frameGeometry.Cutouts.Count);
+        var cutout = frameGeometry.Cutouts[cutoutIndex];
+        if (!cutout.IsClosed() || !WithinRange(cutout.BoundingBox)
+            || spacing * 2 >= System.Math.Min(cutout.BoundingBox.Length, cutout.BoundingBox.Width))
+            return null;
+        var hole = CutoutLatticeFill.Positive(ClipperBridge.ToPath(
+            ClipperBridge.Flatten(cutout, CutoutLatticeFill.FlattenTolerance, circumscribe: false),
+            new Vector()));
+        if (hole.Count < 3)
+            return null;
+        var framePose = new NestJobPlacement(frame.Id, 0, 0, 0, 0);
+        foreach (var rotation in insert.Rotation.EnumerateAngles())
+        {
+            token.ThrowIfCancellationRequested();
+            var region = CutoutLatticeFill.InnerFit(insertGeometry, rotation, hole, spacing);
+            token.ThrowIfCancellationRequested();
+            foreach (var (x, y) in Candidates(region))
+            {
+                token.ThrowIfCancellationRequested();
+                if (!CutoutLatticeFill.Inside(region, x, y))
+                    continue;
+                var pose = new NestJobPlacement(insert.Id, 0, x, y, rotation);
+                if (!NestLayoutCheck.Clears(frameGeometry, framePose, insertGeometry, pose, spacing))
+                    continue;
+                var clears = true;
+                foreach (var other in occupied)
+                {
+                    token.ThrowIfCancellationRequested();
+                    if (NestLayoutCheck.Clears(other.Geometry, other.Pose, insertGeometry, pose, spacing))
+                        continue;
+                    clears = false;
+                    break;
+                }
+                token.ThrowIfCancellationRequested();
+                if (clears)
+                    return pose;
+            }
+        }
+        token.ThrowIfCancellationRequested();
+        return null;
+    }
+
+    private static bool WithinRange(Box box) =>
+        double.IsFinite(box.Left) && double.IsFinite(box.Right)
+        && double.IsFinite(box.Bottom) && double.IsFinite(box.Top)
+        && System.Math.Abs(box.Left) <= MaxCoordinate && System.Math.Abs(box.Right) <= MaxCoordinate
+        && System.Math.Abs(box.Bottom) <= MaxCoordinate && System.Math.Abs(box.Top) <= MaxCoordinate;
+
+    /// <summary>Sample component interiors, then points just inside each boundary toward
+    /// its component's center. This bounded search is not a complete inner-fit solver.</summary>
+    private static IEnumerable<(double X, double Y)> Candidates(PathsD region)
+    {
+        foreach (var path in region.Where(p => p.Count >= 3 && Clipper.IsPositive(p)))
+        {
+            var bounds = Clipper.GetBounds(new PathsD { path });
+            var cx = (bounds.left + bounds.right) / 2;
+            var cy = (bounds.top + bounds.bottom) / 2;
+            yield return (cx, cy);
+            foreach (var point in path)
+                yield return (point.x * 0.99 + cx * 0.01, point.y * 0.99 + cy * 0.01);
+            // Bounded interior samples let a residual insert land beside a partial lattice;
+            // a center/vertex-only sample often lands directly on an earlier copy.
+            for (var y = 1; y <= 9; y++)
+                for (var x = 1; x <= 9; x++)
+                    yield return (bounds.left + (bounds.right - bounds.left) * x / 10,
+                        bounds.top + (bounds.bottom - bounds.top) * y / 10);
+        }
+    }
+}

OpenNest.Engine/Jobs/Cutouts/CutoutPipelinePrepass.cs

@@ -0,0 +1,242 @@
+#nullable enable
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using OpenNest.Engine.Jobs.Adapters;
+
+namespace OpenNest.Engine.Jobs.Cutouts;
+
+/// <summary>Internal-only frame bundles. No normal pipeline caller enables this.</summary>
+internal sealed class CutoutPipelinePrepass
+{
+    // A job with thousands of repeats still offers the residual as ordinary demand;
+    // do not multiply expensive Clipper/Fill preparation by every physical instance.
+    private const int MaxBundlesPerJob = 32;
+    private sealed record Bundle(string FrameId, IReadOnlyList<NestJobPlacement> LocalInserts);
+    private readonly IReadOnlyDictionary<string, Bundle> bundles;
+
+    private CutoutPipelinePrepass(NestJob engineJob, IReadOnlyDictionary<string, Bundle> bundles)
+    {
+        EngineJob = engineJob;
+        this.bundles = bundles;
+    }
+
+    internal NestJob EngineJob { get; }
+
+    internal static CutoutPipelinePrepass? Prepare(NestJob original, CancellationToken token)
+    {
+        token.ThrowIfCancellationRequested();
+        if (original.Plates.Count == 0)
+            return null;
+        // One reservation vector works for every offered stock. Current jobs cannot
+        // represent stock-conditional insert quantities; use the largest spacing.
+        var spacing = original.Plates.Max(p => p.PartSpacing);
+        var remaining = original.Parts.ToDictionary(p => p.Id, p => p.Quantity);
+        var geometry = original.Parts.ToDictionary(p => p.Id, p => JobPartGeometry.TryRead(p.Geometry));
+        var bundles = new Dictionary<string, Bundle>(StringComparer.Ordinal);
+        var byFrame = new Dictionary<string, List<NestJobPart>>(StringComparer.Ordinal);
+        foreach (var frame in original.Parts)
+        {
+            token.ThrowIfCancellationRequested();
+            if (bundles.Count >= MaxBundlesPerJob)
+                break;
+            var profile = geometry[frame.Id];
+            if (profile == null || profile.Cutouts.Count == 0)
+                continue;
+            var proxies = new List<NestJobPart>();
+            byFrame[frame.Id] = proxies;
+            for (var instance = 0; instance < frame.Quantity; instance++)
+            {
+                token.ThrowIfCancellationRequested();
+                if (bundles.Count >= MaxBundlesPerJob)
+                    break;
+                IReadOnlyList<NestJobPlacement>? chosen = null;
+                double frameAngle = 0;
+                // Outer-perimeter symmetry cannot deduplicate asymmetric cutouts.
+                foreach (var angle in frame.Rotation.EnumerateAngles(maxSamples: 16))
+                {
+                    token.ThrowIfCancellationRequested();
+                    if (!FitsOfferedStock(frame, angle, original.Plates))
+                        continue;
+                    var local = new List<NestJobPlacement>();
+                    var available = new Dictionary<string, int>(remaining);
+                    for (var hole = 0; hole < profile.Cutouts.Count; hole++)
+                    {
+                        token.ThrowIfCancellationRequested();
+                        // Flat bundles: frames cannot simultaneously be inserts in another bundle.
+                        var candidates = original.Parts
+                            .Where(p => p.Id != frame.Id && available[p.Id] > 0
+                                && p.Priority == frame.Priority
+                                && geometry[p.Id] is { Cutouts.Count: 0 })
+                            .Select(p => new NestJobPart(p.Id, p.Geometry, available[p.Id],
+                                p.Priority, LocalRotation(p.Rotation, angle)))
+                            .ToArray();
+                        if (candidates.Length == 0)
+                            break;
+                        foreach (var pose in CutoutRouter.Fill(frame, hole, candidates, spacing, token))
+                        {
+                            token.ThrowIfCancellationRequested();
+                            var source = geometry[pose.PartId]!;
+                            var policy = original.Parts.Single(p => p.Id == pose.PartId).Rotation;
+                            if (!policy.Allows(angle + pose.Rotation)
+                                || local.Any(other => !NestLayoutCheck.Clears(
+                                    geometry[other.PartId]!, other, source, pose, spacing)))
+                                continue;
+                            local.Add(pose);
+                            available[pose.PartId]--;
+                        }
+                    }
+                    if (local.Count <= (chosen?.Count ?? 0))
+                        continue;
+                    chosen = local.ToArray();
+                    frameAngle = angle;
+                }
+                if (chosen == null || chosen.Count == 0)
+                    break;
+                var proxyId = $"__cutout-proxy-{frame.Id}-{instance}";
+                if (remaining.ContainsKey(proxyId) || bundles.ContainsKey(proxyId))
+                    throw new InvalidOperationException("Cutout proxy ID collides with a requirement.");
+                bundles.Add(proxyId, new Bundle(frame.Id, chosen));
+                proxies.Add(new NestJobPart(proxyId, frame.Geometry, 1, frame.Priority,
+                    RotationPolicy.Fixed(frameAngle)));
+                remaining[frame.Id]--;
+                foreach (var pose in chosen)
+                    remaining[pose.PartId]--;
+            }
+        }
+        if (bundles.Count == 0)
+            return null;
+        var transformed = new List<NestJobPart>();
+        foreach (var part in original.Parts)
+        {
+            if (byFrame.TryGetValue(part.Id, out var proxies))
+                transformed.AddRange(proxies);
+            if (remaining[part.Id] > 0)
+                transformed.Add(new NestJobPart(part.Id, part.Geometry, remaining[part.Id],
+                    part.Priority, part.Rotation));
+        }
+        return new CutoutPipelinePrepass(new NestJob(transformed, original.Plates,
+            original.Options), bundles);
+    }
+
+    private static RotationPolicy LocalRotation(RotationPolicy original, double frameAngle) =>
+        original.Kind switch
+        {
+            RotationPolicyKind.Automatic => RotationPolicy.Automatic,
+            RotationPolicyKind.Fixed => RotationPolicy.Fixed(original.Start - frameAngle,
+                original.Allow180Equivalent),
+            _ => RotationPolicy.BoundedSweep(original.Start - frameAngle,
+                original.End - frameAngle, original.Step, original.Allow180Equivalent),
+        };
+
+    private static bool FitsOfferedStock(NestJobPart frame, double angle,
+        IReadOnlyList<NestPlateStock> stock)
+    {
+        var part = new Part(DrawingJobMapper.CreateDrawing(frame));
+        part.Rotate(angle);
+        var bounds = NestLayoutCheck.MaterialBounds(part);
+        return stock.Any(s => s.Quantity != 0 && s.Fits(bounds.Length, bounds.Width,
+            NestTolerances.WorkAreaSlack));
+    }
+
+    /// <summary>Reject untrusted accounting before expansion. A failed trial is never bindable,
+    /// including with allowInvalid. Only actually placed proxies consume reserved inserts.</summary>
+    internal bool TryExpand(NestJob original, NestJobResult result, CancellationToken token,
+        out NestJobResult? expanded,
+        out string failure)
+    {
+        expanded = null;
+        failure = "Invalid cutout engine accounting";
+        var parts = EngineJob.Parts.ToDictionary(p => p.Id);
+        var counts = parts.ToDictionary(p => p.Key, _ => 0);
+        var indices = parts.ToDictionary(p => p.Key, _ => new HashSet<int>());
+        var stockById = EngineJob.Plates.ToDictionary(s => s.Id, StringComparer.Ordinal);
+        var used = stockById.ToDictionary(s => s.Key, _ => 0, StringComparer.Ordinal);
+        var expectedIndex = 0;
+        foreach (var sheet in result.Plates)
+        {
+            token.ThrowIfCancellationRequested();
+            if (sheet.PlateIndex != expectedIndex++ || sheet.Placements.Count == 0
+                || !used.ContainsKey(sheet.StockId))
+                return false;
+            used[sheet.StockId]++;
+            foreach (var pose in sheet.Placements)
+            {
+                if (pose.PartId == null || !parts.ContainsKey(pose.PartId)
+                    || pose.InstanceIndex < 0 || !indices[pose.PartId].Add(pose.InstanceIndex)
+                    || ++counts[pose.PartId] > parts[pose.PartId].Quantity)
+                    return false;
+            }
+        }
+        foreach (var row in indices)
+        {
+            token.ThrowIfCancellationRequested();
+            if (row.Value.Any(index => index >= counts[row.Key]))
+                return false;
+        }
+        if (result.Fulfillment.Count != parts.Count || result.StockUsage.Count != used.Count)
+            return false;
+        var seenParts = new HashSet<string>(StringComparer.Ordinal);
+        foreach (var row in result.Fulfillment)
+        {
+            token.ThrowIfCancellationRequested();
+            if (row.PartId == null || !parts.TryGetValue(row.PartId, out var part)
+                || !seenParts.Add(row.PartId)
+                || row.Requested != part.Quantity || row.Placed != counts[row.PartId]
+                || row.Unplaced != part.Quantity - counts[row.PartId])
+                return false;
+        }
+        var seenStock = new HashSet<string>(StringComparer.Ordinal);
+        foreach (var row in result.StockUsage)
+        {
+            token.ThrowIfCancellationRequested();
+            if (row.StockId == null || !stockById.TryGetValue(row.StockId, out var stock)
+                || !seenStock.Add(row.StockId)
+                || row.Used != used[row.StockId]
+                || row.Remaining != stock.Quantity - row.Used)
+                return false;
+        }
+        var complete = parts.Values.All(p => counts[p.Id] == p.Quantity);
+        if (result.Status != (complete ? NestJobStatus.Complete : NestJobStatus.Incomplete)
+            || (complete && result.StopReason != NestJobStopReason.Completed)
+            || (!complete && result.StopReason == NestJobStopReason.Completed))
+            return false;
+
+        var builder = new NestJobResultBuilder(original);
+        foreach (var sheet in result.Plates)
+        {
+            token.ThrowIfCancellationRequested();
+            var poses = new List<(string PartId, double X, double Y, double Rotation)>();
+            foreach (var pose in sheet.Placements)
+            {
+                if (!bundles.TryGetValue(pose.PartId, out var bundle))
+                {
+                    poses.Add((pose.PartId, pose.X, pose.Y, pose.Rotation));
+                    continue;
+                }
+                poses.Add((bundle.FrameId, pose.X, pose.Y, pose.Rotation));
+                var sine = System.Math.Sin(pose.Rotation);
+                var cosine = System.Math.Cos(pose.Rotation);
+                foreach (var local in bundle.LocalInserts)
+                    poses.Add((local.PartId,
+                        pose.X + local.X * cosine - local.Y * sine,
+                        pose.Y + local.X * sine + local.Y * cosine,
+                        pose.Rotation + local.Rotation));
+            }
+            // Canonical stock reference, not an engine-supplied object with altered settings.
+            var stock = original.Plates.Single(s => s.Id == sheet.StockId);
+            try
+            {
+                builder.AddSheet(stock, poses);
+            }
+            catch (Exception ex) when (ex is ArgumentException or InvalidOperationException)
+            {
+                return false;
+            }
+        }
+        token.ThrowIfCancellationRequested();
+        expanded = builder.Build(result.StopReason);
+        return true;
+    }
+}

OpenNest.Engine/Jobs/Cutouts/CutoutRouter.cs

@@ -0,0 +1,144 @@
+#nullable enable
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+
+namespace OpenNest.Engine.Jobs.Cutouts;
+
+/// <summary>Internal frame-local cutout proposal. Never changes demand, stock or a live plate.</summary>
+/// <remarks>Area ratio selects search order, not placement permission. The small-insert path
+/// prefers a shifted partial lattice; the middle compares it with occupied-aware NFP search;
+/// the large-insert path tries NFP first. All accepted poses are clearance-checked.
+/// Fill's equal-score pose nondeterminism remains PM c98c21bd.</remarks>
+internal static class CutoutRouter
+{
+    // Calibrated as search-order hints, not hard geometry cutoffs. Round-hole neutral tests
+    // show a Fill win at 0.204, so the original proposed >0.20 NFP-only rule loses copies.
+    internal const double SmallRatio = 0.10;
+    internal const double LargeRatio = 0.35;
+
+    internal static IReadOnlyList<NestJobPlacement> Fill(NestJobPart frame, int cutoutIndex,
+        IReadOnlyList<NestJobPart> inserts, double spacing, CancellationToken token = default) =>
+        Fill(frame, cutoutIndex, inserts, spacing, null, token);
+
+    /// <summary>Optional internal diagnostic receives only poses from the chosen proposal,
+    /// after indexing; true marks a retained lattice seed, false a residual NFP pose.</summary>
+    internal static IReadOnlyList<NestJobPlacement> Fill(NestJobPart frame, int cutoutIndex,
+        IReadOnlyList<NestJobPart> inserts, double spacing,
+        Action<NestJobPlacement, bool>? observeAccepted, CancellationToken token = default)
+    {
+        ArgumentNullException.ThrowIfNull(frame);
+        ArgumentNullException.ThrowIfNull(inserts);
+        token.ThrowIfCancellationRequested();
+        if (!double.IsFinite(spacing) || spacing < 0 || spacing > 100)
+            return Array.Empty<NestJobPlacement>();
+        var frameGeometry = JobPartGeometry.TryRead(frame.Geometry);
+        if (frameGeometry == null)
+            return Array.Empty<NestJobPlacement>();
+        ArgumentOutOfRangeException.ThrowIfNegative(cutoutIndex);
+        ArgumentOutOfRangeException.ThrowIfGreaterThanOrEqual(cutoutIndex, frameGeometry.Cutouts.Count);
+        var hole = frameGeometry.Cutouts[cutoutIndex];
+        if (!hole.IsClosed() || !Supported(frameGeometry.Bounds) || !Supported(hole.BoundingBox))
+            return Array.Empty<NestJobPlacement>();
+        if (inserts.Any(p => p == null || !SupportedGeometry(p)))
+            return Array.Empty<NestJobPlacement>();
+        if (inserts.Select(p => p.Id).Distinct(StringComparer.Ordinal).Count() != inserts.Count
+            || inserts.Any(p => p.Id == frame.Id))
+            throw new ArgumentException("Requirement IDs must be distinct from the frame and each other.",
+                nameof(inserts));
+
+        var accepted = new List<NestJobPlacement>();
+        var occupied = new List<(JobPartGeometry Geometry, NestJobPlacement Pose)>();
+        var holeArea = System.Math.Abs(hole.Area());
+        // Preserve caller requirement order: priorities are a whole-job concern, not inferred here.
+        foreach (var part in inserts)
+        {
+            token.ThrowIfCancellationRequested();
+            var geometry = JobPartGeometry.Read(part.Geometry);
+            var ratio = geometry.MaterialArea / holeArea;
+            // Unsupported or degenerate material cannot establish a useful routing ratio;
+            // NFP retains its own fail-closed checks and the bounded lattice is not tried.
+            var tryLattice = part.Quantity >= 3 && double.IsFinite(ratio) && ratio > 0;
+            var nfpFirst = !tryLattice || ratio >= LargeRatio;
+            var compareBoth = tryLattice && ratio >= SmallRatio && ratio < LargeRatio;
+            var nfp = nfpFirst ? Nfp(Array.Empty<NestJobPlacement>()) : null;
+            var lattice = tryLattice && (!nfpFirst || nfp!.Count < part.Quantity)
+                ? CutoutLatticeFill.Fill(frame, cutoutIndex, part, part.Quantity, spacing,
+                    CutoutLatticeFill.DefaultShiftSteps, occupied, token)
+                : Array.Empty<NestJobPlacement>();
+            IReadOnlyList<NestJobPlacement> chosen;
+            var retainedLattice = 0;
+            if (compareBoth || (nfpFirst && lattice.Count > 0))
+            {
+                nfp ??= Nfp(Array.Empty<NestJobPlacement>());
+                var fromLattice = Complete(lattice);
+                chosen = fromLattice.Count > nfp.Count ? fromLattice : nfp;
+                if (ReferenceEquals(chosen, fromLattice))
+                    retainedLattice = lattice.Count;
+            }
+            else if (nfpFirst)
+                chosen = nfp!;
+            else
+            {
+                // A single Fill copy ties one NFP pose; prefer NFP's stable candidate
+                // order, but retain the lattice copy if bounded NFP found nothing.
+                var seed = lattice.Count > 1 ? lattice : Array.Empty<NestJobPlacement>();
+                chosen = Complete(seed);
+                if (chosen.Count == 0 && lattice.Count == 1)
+                    chosen = lattice;
+                retainedLattice = ReferenceEquals(chosen, lattice) ? lattice.Count : seed.Count;
+            }
+
+            var localIndex = 0;
+            foreach (var pose in chosen)
+            {
+                token.ThrowIfCancellationRequested();
+                var indexed = pose with { InstanceIndex = accepted.Count(p => p.PartId == part.Id) };
+                accepted.Add(indexed);
+                occupied.Add((geometry, indexed));
+                observeAccepted?.Invoke(indexed, localIndex++ < retainedLattice);
+            }
+
+            IReadOnlyList<NestJobPlacement> Complete(IReadOnlyList<NestJobPlacement> seed)
+            {
+                if (seed.Count >= part.Quantity)
+                    return seed;
+                var result = new List<NestJobPlacement>(seed);
+                result.AddRange(Nfp(seed));
+                return result;
+            }
+
+            IReadOnlyList<NestJobPlacement> Nfp(IReadOnlyList<NestJobPlacement> seed)
+            {
+                var result = new List<NestJobPlacement>();
+                var local = new List<(JobPartGeometry Geometry, NestJobPlacement Pose)>(occupied);
+                local.AddRange(seed.Select(p => (geometry, p)));
+                while (seed.Count + result.Count < part.Quantity)
+                {
+                    token.ThrowIfCancellationRequested();
+                    var pose = CutoutNfpProposal.Find(frame, cutoutIndex, part, spacing, local, token);
+                    if (pose == null)
+                        break;
+                    result.Add(pose);
+                    local.Add((geometry, pose));
+                }
+                return result;
+            }
+        }
+        token.ThrowIfCancellationRequested();
+        return accepted.ToArray();
+    }
+
+    private static bool SupportedGeometry(NestJobPart part)
+    {
+        var geometry = JobPartGeometry.TryRead(part.Geometry);
+        return geometry != null && Supported(geometry.Bounds);
+    }
+
+    private static bool Supported(OpenNest.Geometry.Box box) =>
+        double.IsFinite(box.Left) && double.IsFinite(box.Right)
+        && double.IsFinite(box.Bottom) && double.IsFinite(box.Top)
+        && System.Math.Abs(box.Left) <= 1e8 && System.Math.Abs(box.Right) <= 1e8
+        && System.Math.Abs(box.Bottom) <= 1e8 && System.Math.Abs(box.Top) <= 1e8;
+}

OpenNest.Engine/Jobs/NestCostSummary.cs

@@ -0,0 +1,39 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using OpenNest.Geometry;
+
+namespace OpenNest.Engine.Jobs;
+
+public sealed record NestStockCost(string StockId, int Used, double? Cost, double GrossSubtotal);
+
+/// <summary>Costs of validated physical sheets, excluding unplaced-demand penalties.</summary>
+public sealed record NestCostSummary(string Basis, IReadOnlyList<NestStockCost> Stock,
+    double GrossTotal, double SalvageCredit, double NetScore)
+{
+    public static NestCostSummary FromAccepted(NestPipelineResult result)
+    {
+        if (!result.CanKeep || !result.IsValid)
+            throw new ArgumentException("Cost reporting requires a validated proposal.", nameof(result));
+        var stock = result.Job.Plates.Select(s =>
+        {
+            var used = result.Plates.Count(p => p.Stock.Id == s.Id);
+            return new NestStockCost(s.Id, used, s.Cost,
+                used == 0 ? 0 : NestJobCost.RequireFinite(used * NestJobCost.GrossSheetCost(s)));
+        }).ToArray();
+        var gross = NestJobCost.RequireFinite(stock.Sum(s => s.GrossSubtotal));
+        var net = NestJobCost.RequireFinite(result.Plates.Sum(sheet =>
+        {
+            if (sheet.Parts.Count == 0 || result.Job.Options.SalvageRate == 0
+                || result.Job.Options.MinimumSalvageDimension <= 0)
+                return NestJobCost.GrossSheetCost(sheet.Stock);
+            var bounds = sheet.Parts.Select(NestLayoutCheck.MaterialBounds).ToArray();
+            var left = bounds.Min(b => b.Left);
+            var bottom = bounds.Min(b => b.Bottom);
+            return NestJobCost.NetSheetCost(result.Job.Options, sheet.Stock,
+                new Box(left, bottom, bounds.Max(b => b.Right) - left, bounds.Max(b => b.Top) - bottom));
+        }));
+        return new NestCostSummary(NestJobCost.UsesExplicitCosts(result.Job)
+            ? "supplied-cost" : "area", stock, gross, NestJobCost.RequireFinite(gross - net), net);
+    }
+}

OpenNest.Engine/Jobs/NestJob.cs

@@ -16,6 +16,7 @@ public sealed class NestJob
         Parts = Own(parts);
         Plates = Own(plates);
         Options = options ?? new NestJobOptions();
+        NestJobValidator.ValidateStockCosts(Plates);
         if (
             Parts.Select(p => p.Id).Distinct(StringComparer.Ordinal).Count() != Parts.Count
             || Plates.Select(p => p.Id).Distinct(StringComparer.Ordinal).Count() != Plates.Count

OpenNest.Engine/Jobs/NestJobCandidateComparer.cs

@@ -4,10 +4,13 @@ using System.Linq;
 
 namespace OpenNest.Engine.Jobs;
 
-/// <summary>Ranks independent plate trials: priority fulfillment, sheet area, placement envelope, then input order.</summary>
+/// <summary>Ranks independent plate trials: priority fulfillment, sheet cost, placement envelope, then input order.</summary>
 public sealed class NestJobCandidateComparer
 {
     private readonly IReadOnlyList<NestJobPart> parts;
+    private readonly NestJob job;
+
+    public NestJobCandidateComparer(NestJob job) : this(job.Parts) => this.job = job;
 
     public NestJobCandidateComparer(IReadOnlyList<NestJobPart> parts)
     {
@@ -36,7 +39,7 @@ public sealed class NestJobCandidateComparer
                 return leftCount.CompareTo(rightCount);
         }
 
-        var area = Area(rightStock).CompareTo(Area(leftStock));
+        var area = Score(right, rightStock).CompareTo(Score(left, leftStock));
         if (area != 0)
             return area;
 
@@ -52,7 +55,10 @@ public sealed class NestJobCandidateComparer
             parts.First(part => part.Id == placement.PartId).Priority == priority
         );
 
-    private static double Area(NestPlateStock stock) => stock.Size.Width * stock.Size.Length;
+    private double Score(PlateCandidate candidate, NestPlateStock stock) =>
+        job != null && stock.Cost.HasValue
+            ? NestJobCost.NetSheetCost(job, new NestJobPlateResult(0, stock, candidate.Placements))
+            : NestJobCost.GrossSheetCost(stock);
 
     private static double Envelope(PlateCandidate candidate)
     {

OpenNest.Engine/Jobs/NestJobCost.cs

@@ -1,10 +1,11 @@
+using System;
 using System.Linq;
 using OpenNest.Engine.Jobs.Adapters;
 using OpenNest.Geometry;
 
 namespace OpenNest.Engine.Jobs;
 
-/// <summary>Benchmark scoring primitives. Lower costs represent less sheet consumption.</summary>
+/// <summary>Generic per-sheet scoring; unspecified costs retain legacy area scores.</summary>
 public static class NestJobCost
 {
     /// <summary>
@@ -66,16 +67,35 @@ public static class NestJobCost
         return area - options.SalvageRate * salvage;
     }
 
-    /// <summary>Largest offered sheet area, charged by the benchmark per unplaced part.</summary>
+    public static bool UsesExplicitCosts(NestJob job) =>
+        job.Plates.Any(s => s.Quantity != 0 && s.Cost.HasValue);
+
+    public static double RequireFinite(double value) => double.IsFinite(value) ? value
+        : throw new OverflowException("Stock cost arithmetic exceeded the finite scoring range.");
+
+    public static double GrossSheetCost(NestPlateStock stock) => RequireFinite(stock.Cost ?? stock.Area);
+
+    public static double NetSheetCost(NestJob job, NestJobPlateResult sheet) =>
+        PriceArea(sheet.Stock, NetSheetArea(job, sheet));
+
+    public static double NetSheetCost(NestJobOptions options, NestPlateStock stock, Box envelope) =>
+        PriceArea(stock, NetSheetArea(options, stock, envelope));
+
+    private static double PriceArea(NestPlateStock stock, double area) =>
+        RequireFinite(stock.Cost is double cost ? cost * (area / stock.Area) : area);
+
+    /// <summary>Largest offered sheet score, charged per unplaced part.</summary>
     public static double UnplacedPartPenalty(NestJob job) =>
-        job.Plates.Count == 0 ? 0 : job.Plates.Max(stock => stock.Size.Width * stock.Size.Length);
+        job.Plates.Count == 0 ? 0 : UsesExplicitCosts(job)
+            ? job.Plates.Where(s => s.Quantity != 0).Max(GrossSheetCost)
+            : job.Plates.Max(s => RequireFinite(s.Area));
 
     /// <summary>
-    /// Sum of net sheet areas plus unplaced quantity times the largest offered sheet area.
+    /// Sum of net sheet costs plus unplaced quantity times the largest offered sheet score.
     /// Matches the benchmark for a valid run; this method does not validate the result.
     /// </summary>
     public static double Evaluate(NestJob job, NestJobResult result) =>
-        result.Plates.Sum(sheet => NetSheetArea(job, sheet))
+        RequireFinite(result.Plates.Sum(sheet => NetSheetCost(job, sheet))
         + System.Math.Max(0, job.Parts.Sum(part => part.Quantity)
-            - result.Plates.Sum(sheet => sheet.Placements.Count)) * UnplacedPartPenalty(job);
+            - result.Plates.Sum(sheet => sheet.Placements.Count)) * UnplacedPartPenalty(job));
 }

OpenNest.Engine/Jobs/NestJobRunner.cs

@@ -38,7 +38,7 @@ public sealed class NestJobRunner : INestingEngine
         var placed = job.Parts.ToDictionary(part => part.Id, _ => 0, StringComparer.Ordinal);
         var parts = job.Parts.ToDictionary(part => part.Id, StringComparer.Ordinal);
         var used = job.Plates.ToDictionary(stock => stock.Id, _ => 0, StringComparer.Ordinal);
-        var comparer = new NestJobCandidateComparer(job.Parts);
+        var comparer = new NestJobCandidateComparer(job);
         var nester =
             job.Parts.Count == 0
                 ? null

OpenNest.Engine/Jobs/NestJobValidator.cs

@@ -10,11 +10,13 @@ public static class NestJobValidator
     public static void Validate(NestJob job)
     {
         ArgumentNullException.ThrowIfNull(job);
+        ValidateStockCosts(job.Plates);
         foreach (var stock in job.Plates)
         {
             var edges = stock.EdgeSpacing;
             if (
-                !Positive(stock.Size.Width)
+                !Positive(stock.Area)
+                || !Positive(stock.Size.Width)
                 || !Positive(stock.Size.Length)
                 || !Nonnegative(stock.PartSpacing)
                 || !Nonnegative(edges.Left)
@@ -61,6 +63,14 @@ public static class NestJobValidator
         }
     }
 
+    public static void ValidateStockCosts(IEnumerable<NestPlateStock> stocks)
+    {
+        var available = stocks.Where(s => s.Quantity != 0).ToArray();
+        if (available.Any(s => s.Cost.HasValue) && available.Any(s => !s.Cost.HasValue))
+            throw new ArgumentException("Specify a positive cost for every available stock row or omit all costs. Missing: "
+                + string.Join(", ", available.Where(s => !s.Cost.HasValue).Select(s => s.Id)));
+    }
+
     internal static void ValidateCandidate(
         PlateCandidate candidate,
         NestPlateStock stock,

OpenNest.Engine/Jobs/NestLayoutCheck.cs

@@ -231,7 +231,8 @@ public static class NestLayoutCheck
     private static bool SameSettings(NestPlateStock expected, NestPlateStock actual) =>
         ReferenceEquals(expected, actual)
         || (
-            expected.Size.Equals(actual.Size)
+            expected.Cost == actual.Cost
+            && expected.Size.Equals(actual.Size)
             && expected.PartSpacing.IsEqualTo(actual.PartSpacing)
             && expected.EdgeSpacing.Left.IsEqualTo(actual.EdgeSpacing.Left)
             && expected.EdgeSpacing.Right.IsEqualTo(actual.EdgeSpacing.Right)

OpenNest.Engine/Jobs/NestPipeline.cs

@@ -4,6 +4,7 @@ using System.Diagnostics;
 using System.Linq;
 using System.Threading;
 using OpenNest.Engine.Jobs.Adapters;
+using OpenNest.Engine.Jobs.Cutouts;
 
 namespace OpenNest.Engine.Jobs;
 
@@ -36,7 +37,8 @@ public sealed class NestPipelineResult
         IReadOnlyList<string> violations,
         bool canKeep,
         TimeSpan solveTime,
-        TimeSpan validationTime
+        TimeSpan validationTime,
+        IReadOnlyDictionary<string, Drawing> drawingsByPartId
     )
     {
         EngineName = engineName;
@@ -47,6 +49,7 @@ public sealed class NestPipelineResult
         CanKeep = canKeep;
         SolveTime = solveTime;
         ValidationTime = validationTime;
+        DrawingsByPartId = drawingsByPartId;
     }
 
     public string EngineName { get; }
@@ -62,6 +65,7 @@ public sealed class NestPipelineResult
     public NestJobStopReason StopReason => Raw.StopReason;
     public TimeSpan SolveTime { get; }
     public TimeSpan ValidationTime { get; }
+    internal IReadOnlyDictionary<string, Drawing> DrawingsByPartId { get; }
 }
 
 /// <summary>
@@ -72,6 +76,15 @@ public sealed class NestPipelineResult
 /// </summary>
 public static class NestPipeline
 {
+    private sealed class PreviewProgress(IProgress<NestJobProgress> inner) : IProgress<NestJobProgress>
+    {
+        public void Report(NestJobProgress value)
+        {
+            if (value != null && value.Stage == NestJobStage.EvaluatingCandidate)
+                inner.Report(value with { CommittedPlates = 0, CommittedParts = 0 });
+        }
+    }
+
     /// <summary>Resolves <see cref="NestPipelineRequest.EngineName"/> through
     /// <see cref="NestingEngineRegistry"/>; unknown names throw <see cref="NotSupportedException"/>.
     /// Engine cancellation propagates unchanged.</summary>
@@ -93,6 +106,32 @@ public static class NestPipeline
         NestPipelineRequest request,
         IProgress<NestJobProgress> progress = null,
         CancellationToken token = default
+    ) => RunCore(engine, engineName, request, progress, token, cutoutPreview: false);
+
+    /// <summary>Internal test-only integration trial. Normal Run never prepares cutouts;
+    /// this entry point must not be called by production front ends before cutting/post gates.</summary>
+    internal static NestPipelineResult RunCutoutPreview(
+        INestingEngine engine,
+        string engineName,
+        NestPipelineRequest request,
+        IProgress<NestJobProgress> progress = null,
+        CancellationToken token = default
+    ) => RunCore(engine, engineName, request, progress, token, cutoutPreview: true);
+
+    internal static NestPipelineResult RunCutoutPreview(
+        NestPipelineRequest request,
+        IProgress<NestJobProgress> progress = null,
+        CancellationToken token = default
+    ) => RunCutoutPreview(NestingEngineRegistry.Create(request.EngineName),
+        request.EngineName, request, progress, token);
+
+    private static NestPipelineResult RunCore(
+        INestingEngine engine,
+        string engineName,
+        NestPipelineRequest request,
+        IProgress<NestJobProgress> progress,
+        CancellationToken token,
+        bool cutoutPreview
     )
     {
         ArgumentNullException.ThrowIfNull(engine);
@@ -115,10 +154,15 @@ public static class NestPipeline
 
         var job = new NestJob(parts, request.Stock, request.Options);
         NestJobValidator.Validate(job);
+        var prepass = cutoutPreview ? CutoutPipelinePrepass.Prepare(job, token) : null;
+        var engineJob = prepass?.EngineJob ?? job;
+        if (prepass != null)
+            NestJobValidator.Validate(engineJob);
 
         var clock = Stopwatch.StartNew();
         var raw =
-            engine.Solve(job, progress, token)
+            engine.Solve(engineJob, prepass == null || progress == null
+                ? progress : new PreviewProgress(progress), token)
             ?? throw new InvalidOperationException($"Engine '{engineName}' returned no result.");
         var solveTime = clock.Elapsed;
         token.ThrowIfCancellationRequested();
@@ -129,8 +173,36 @@ public static class NestPipeline
             kv => kv.Value.Name ?? kv.Key,
             StringComparer.Ordinal
         );
-        var violations = NestLayoutCheck.Violations(job, raw, names, out var canKeep);
+        var checkedNames = prepass == null ? names : engineJob.Parts.ToDictionary(p => p.Id,
+            p => names.GetValueOrDefault(p.Id, p.Id), StringComparer.Ordinal);
+        var violations = NestLayoutCheck.Violations(engineJob, raw, checkedNames, out var canKeep).ToList();
+        if (prepass != null)
+        {
+            // A compound may be physically invalid even when its envelope is legal.
+            // Refuse every unverified trial, including with explicit invalid-result consent.
+            var failure = "Cutout engine output failed reconciliation";
+            if (violations.Count == 0 && prepass.TryExpand(job, raw, token, out var expanded, out failure))
+            {
+                raw = expanded;
+                violations.AddRange(NestLayoutCheck.Violations(job, raw, names, out var physicalKeep));
+                if (raw.Status != NestJobStatus.Complete)
+                    violations.Add("Cutout engine did not complete the transformed job; unplaced frames' reserved inserts remain unplaced in the original job");
+                canKeep = physicalKeep && violations.Count == 0;
+            }
+            else
+            {
+                if (violations.Count == 0)
+                    violations.Add(failure);
+                canKeep = false;
+            }
+        }
+        var freshness = NestPipelineDrawingFreshness.Changes(job, drawingsByPartId);
+        violations.AddRange(freshness);
+        if (freshness.Count > 0)
+            canKeep = false;
         var validationTime = clock.Elapsed;
+        if (canKeep && violations.Count == 0)
+            _ = NestJobCost.Evaluate(job, raw);
 
         var plates = canKeep
             ? raw.Plates.Select(sheet => new ProposedPlate(
@@ -141,6 +213,31 @@ public static class NestPipeline
             .ToList()
             : new List<ProposedPlate>();
 
+        // Binding clones the caller's current Program; a concurrent edit during binding
+        // must not return parts whose bytes differ from the already validated snapshot.
+        if (canKeep)
+        {
+            var changes = NestPipelineDrawingFreshness.Changes(job, drawingsByPartId).ToList();
+            changes.AddRange(NestPipelineDrawingFreshness.BoundChanges(job, raw, plates, drawingsByPartId));
+            if (changes.Count > 0)
+            {
+                violations.AddRange(changes);
+                plates.Clear();
+                canKeep = false;
+            }
+        }
+
+        token.ThrowIfCancellationRequested();
+        if (prepass != null && canKeep)
+        {
+            var count = 0;
+            for (var i = 0; i < raw.Plates.Count; i++)
+            {
+                count += raw.Plates[i].Placements.Count;
+                progress?.Report(new NestJobProgress(NestJobStage.PlateCommitted,
+                    raw.Plates[i].StockId, i, i + 1, count));
+            }
+        }
         token.ThrowIfCancellationRequested();
         return new NestPipelineResult(
             engineName,
@@ -150,7 +247,8 @@ public static class NestPipeline
             violations,
             canKeep,
             solveTime,
-            validationTime
+            validationTime,
+            drawingsByPartId
         );
     }
 }

OpenNest.Engine/Jobs/NestPipelineCommit.cs

@@ -20,6 +20,11 @@ public static class NestPipelineCommit
         token.ThrowIfCancellationRequested();
         if (!result.CanKeep || (!result.IsValid && !allowInvalid))
             throw new InvalidOperationException("The nesting result cannot be committed without a keepable layout and explicit consent to its violations.");
+        if (NestPipelineDrawingFreshness.Changes(result.Job, result.DrawingsByPartId).Count > 0
+            || NestPipelineDrawingFreshness.BoundChanges(result.Job, result.Raw,
+                result.Plates, result.DrawingsByPartId).Count > 0)
+            throw new InvalidOperationException("A drawing or proposed part changed after the nesting proposal was validated; run Auto Nest again.");
+        token.ThrowIfCancellationRequested();
 
         var applied = new List<Plate>();
         // Commit is synchronous on the caller's owning thread. Cancellation is checked

OpenNest.Engine/Jobs/NestPipelineDrawingFreshness.cs

@@ -0,0 +1,99 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using OpenNest.Engine.Jobs.Adapters;
+using OpenNest.Geometry;
+
+namespace OpenNest.Engine.Jobs;
+
+/// <summary>Refuse a proposal when a caller drawing no longer matches its checked snapshot.</summary>
+internal static class NestPipelineDrawingFreshness
+{
+    internal static IReadOnlyList<string> Changes(NestJob job,
+        IReadOnlyDictionary<string, Drawing> drawings)
+    {
+        var changed = new List<string>();
+        foreach (var requirement in job.Parts)
+        {
+            if (!drawings.TryGetValue(requirement.Id, out var drawing)
+                || drawing?.Program == null)
+            {
+                changed.Add($"Drawing for '{requirement.Id}' changed after the nesting snapshot");
+                continue;
+            }
+            try
+            {
+                var current = PartGeometrySnapshot.FromProgram(drawing.Program);
+                if (Same(requirement.Geometry, current))
+                    continue;
+            }
+            catch (Exception ex) when (ex is ArgumentException or NotSupportedException
+                or InvalidOperationException)
+            {
+                // A now-unsupported program is not the geometry that was checked.
+            }
+            changed.Add($"Drawing '{drawing.Name ?? requirement.Id}' changed after the nesting snapshot");
+        }
+        return changed;
+    }
+
+    /// <summary>Check the actual cloned programs, not only the drawing before/after
+    /// binding. A transient edit during Clone may leave the drawing unchanged.</summary>
+    internal static IReadOnlyList<string> BoundChanges(NestJob job, NestJobResult raw,
+        IReadOnlyList<ProposedPlate> plates, IReadOnlyDictionary<string, Drawing> drawings)
+    {
+        var changed = new List<string>();
+        var requirements = job.Parts.ToDictionary(p => p.Id, StringComparer.Ordinal);
+        if (plates.Count != raw.Plates.Count)
+            return new[] { "Bound plate count changed after validation" };
+        for (var sheetIndex = 0; sheetIndex < plates.Count; sheetIndex++)
+        {
+            var poses = raw.Plates[sheetIndex].Placements;
+            var bound = plates[sheetIndex].Parts;
+            if (bound.Count != poses.Count)
+                return new[] { "Bound part count changed after validation" };
+            for (var index = 0; index < poses.Count; index++)
+            {
+                var pose = poses[index];
+                var actual = bound[index];
+                if (pose.PartId == null || !requirements.TryGetValue(pose.PartId, out var requirement)
+                    || !drawings.TryGetValue(pose.PartId, out var drawing)
+                    || !ReferenceEquals(actual.BaseDrawing, drawing))
+                    return new[] { "A bound part no longer matches its requirement" };
+                try
+                {
+                    var expected = new Part(DrawingJobMapper.CreateDrawing(requirement));
+                    expected.Rotate(pose.Rotation);
+                    expected.Location = new Vector(pose.X, pose.Y);
+                    if (Same(PartGeometrySnapshot.FromProgram(expected.Program),
+                            PartGeometrySnapshot.FromProgram(actual.Program))
+                        && Bits(expected.Location.X) == Bits(actual.Location.X)
+                        && Bits(expected.Location.Y) == Bits(actual.Location.Y)
+                        && Bits(expected.Rotation) == Bits(actual.Rotation))
+                        continue;
+                }
+                catch (Exception ex) when (ex is ArgumentException or NotSupportedException
+                    or InvalidOperationException)
+                {
+                    // A changed/unsupported program cannot represent the checked pose.
+                }
+                changed.Add($"Bound part for '{drawing.Name ?? requirement.Id}' changed after validation");
+            }
+        }
+        return changed;
+    }
+
+    private static bool Same(PartGeometrySnapshot a, PartGeometrySnapshot b) =>
+        a.Mode == b.Mode && a.Motions.Count == b.Motions.Count
+        && a.Motions.Zip(b.Motions).All(pair =>
+            pair.First.Type == pair.Second.Type
+            && Bits(pair.First.X) == Bits(pair.Second.X)
+            && Bits(pair.First.Y) == Bits(pair.Second.Y)
+            && Bits(pair.First.CenterX) == Bits(pair.Second.CenterX)
+            && Bits(pair.First.CenterY) == Bits(pair.Second.CenterY)
+            && pair.First.Rotation == pair.Second.Rotation
+            && pair.First.Layer == pair.Second.Layer
+            && pair.First.Suppressed == pair.Second.Suppressed);
+
+    private static long Bits(double value) => BitConverter.DoubleToInt64Bits(value);
+}

OpenNest.Engine/Jobs/NestPlateStock.cs

@@ -16,7 +16,14 @@ public sealed class NestPlateStock
         Spacing edgeSpacing = default,
         int quadrant = 1
     )
+        : this(id, size, quantity, partSpacing, edgeSpacing, quadrant, null) { }
+
+    public NestPlateStock(string id, Size size, int? quantity, double partSpacing,
+        Spacing edgeSpacing, int quadrant, double? cost)
     {
+        if (cost.HasValue && (!double.IsFinite(cost.Value) || cost.Value <= 0))
+            throw new ArgumentOutOfRangeException(nameof(cost), $"Stock {id}: cost must be finite and positive, or null.");
+        Cost = cost;
         ArgumentException.ThrowIfNullOrWhiteSpace(id);
         if (quantity < 0)
             throw new ArgumentOutOfRangeException(nameof(quantity));
@@ -36,6 +43,8 @@ public sealed class NestPlateStock
         );
     }
 
+    /// <summary>Generic per-physical-sheet cost; null selects area scoring.</summary>
+    public double? Cost { get; }
     public string Id { get; }
     public Size Size { get; }
 

OpenNest.Engine/Jobs/NestStockBuilder.cs

@@ -29,9 +29,11 @@ public static class NestStockBuilder
                 quantityPerOption,
                 template.PartSpacing,
                 template.EdgeSpacing,
-                template.Quadrant
+                template.Quadrant,
+                option.Cost == 0 ? null : option.Cost
             ));
         }
+        NestJobValidator.ValidateStockCosts(stock);
         return stock.AsReadOnly();
     }
 

OpenNest.Engine/Jobs/StockLadderNestingEngine.cs

@@ -9,7 +9,7 @@ namespace OpenNest.Engine.Jobs;
 
 /// <summary>
 /// Caller-stock-only allocation followed by bounded adjacent-sheet repacking. All replacements
-/// must reproduce exactly the removed demand and reduce net sheet area; inventory is transactional.
+/// must reproduce exactly the removed demand and reduce net sheet cost; inventory is transactional.
 /// This is a deterministic heuristic, not an optimality or geometric impossibility proof.
 /// </summary>
 public sealed class StockLadderNestingEngine : INestingEngine
@@ -97,8 +97,8 @@ public sealed class StockLadderNestingEngine : INestingEngine
                 // Initial construction only: material area, never raw part counts. Repacking below
                 // compares EXACTLY equivalent demand, and never replaces a sheet by a partial fill.
                 var value =
-                    NestJobCost.NetSheetArea(job, sheet) / candidate.Placements.Sum(p => areas[p.PartId]);
+                    NestJobCost.RequireFinite(NestJobCost.NetSheetCost(job, sheet) / candidate.Placements.Sum(p => areas[p.PartId]));
-                if (value < score - 1e-9)
+                if (value < score - (stock.Cost.HasValue ? 0 : 1e-9))
                 {
                     winner = sheet;
                     score = value;
@@ -188,7 +188,7 @@ public sealed class StockLadderNestingEngine : INestingEngine
                     var demand = old.SelectMany(s => s.Placements)
                         .GroupBy(p => p.PartId)
                         .ToDictionary(g => g.Key, g => g.Count());
-                var baseline = old.Sum(s => NestJobCost.NetSheetArea(job, s));
+                    var baseline = NestJobCost.RequireFinite(old.Sum(s => NestJobCost.NetSheetCost(job, s)));
                     NestJobPlateResult replacement = null;
                     foreach (var stock in job.Plates)
                     {
@@ -198,8 +198,8 @@ public sealed class StockLadderNestingEngine : INestingEngine
                             continue;
                         // Even the maximum possible salvage credit cannot beat the incumbent.
                         var lowerBound =
-                        stock.Size.Width * stock.Size.Length * (1 - job.Options.SalvageRate);
+                            NestJobCost.GrossSheetCost(stock) * (1 - job.Options.SalvageRate);
-                    if (lowerBound >= baseline - 1e-9)
+                        if (lowerBound >= baseline - (stock.Cost.HasValue ? 0 : 1e-9))
                             continue;
                         if (demand.Keys.Any(id => !feasible[id].Contains(stock.Id)))
                             continue;
@@ -215,8 +215,8 @@ public sealed class StockLadderNestingEngine : INestingEngine
                         if (demand.Any(kv => !actual.TryGetValue(kv.Key, out var n) || n != kv.Value))
                             continue;
                         var trial = new NestJobPlateResult(index, stock, candidate.Placements);
-                    var cost = NestJobCost.NetSheetArea(job, trial);
+                        var cost = NestJobCost.NetSheetCost(job, trial);
-                    if (cost >= baseline - 1e-9)
+                        if (cost >= baseline - (stock.Cost.HasValue ? 0 : 1e-9))
                             continue;
                         baseline = cost;
                         replacement = trial;

OpenNest.Engine/NestingEngines/Default/DefaultNestingEngine.cs

@@ -100,7 +100,7 @@ public sealed class DefaultNestingEngine : INestingEngine
         }
     }
 
-    private sealed record Scored(NestJobResult Result, bool Valid, int Unplaced, double Cost, int Order)
+    private sealed record Scored(NestJobResult Result, bool Valid, int Unplaced, double Cost, int Order, bool Priced)
     {
         public static Scored Of(NestJob job, NestJobResult result, int order)
         {
@@ -109,7 +109,7 @@ public sealed class DefaultNestingEngine : INestingEngine
             var unplaced = System.Math.Max(0, job.Parts.Sum(p => p.Quantity) - placed);
             // Cost needs every placement to name a known part, which only a valid result guarantees.
             var cost = valid ? NestJobCost.Evaluate(job, result) : double.PositiveInfinity;
-            return new Scored(result, valid, unplaced, cost, order);
+            return new Scored(result, valid, unplaced, cost, order, NestJobCost.UsesExplicitCosts(job));
         }
 
         public bool IsBetterThan(Scored other)
@@ -118,6 +118,8 @@ public sealed class DefaultNestingEngine : INestingEngine
                 return Valid;
             if (Unplaced != other.Unplaced)
                 return Unplaced < other.Unplaced;
+            if (Priced && Cost != other.Cost)
+                return Cost < other.Cost;
             var scale = System.Math.Max(1, System.Math.Max(System.Math.Abs(Cost), System.Math.Abs(other.Cost)));
             if (double.IsFinite(Cost) && double.IsFinite(other.Cost) && System.Math.Abs(Cost - other.Cost) > 1e-9 * scale)
                 return Cost < other.Cost;

OpenNest.Engine/NestingEngines/Irregular/IrregularNestingEngine.cs

@@ -14,7 +14,7 @@ namespace OpenNest.Engine.NestingEngines.Irregular;
 /// (part type, orientation) as inner-fit rectangle minus no-fit polygons, and repeatedly places
 /// either the largest part that fills a gap behind the packing front, or the part that advances
 /// the front least per unit of area covered. Across sheets, every available stock size is
-/// trial-packed and the one with the lowest estimated whole-job cost (its own net area plus the
+/// trial-packed and the one with the lowest estimated whole-job cost (its own net cost plus the
 /// remaining demand at the best efficiency seen) is committed. A handful of deterministic
 /// strategy variants (front direction, area exponent) run whole-job, and the cheapest wins.
 ///
@@ -120,7 +120,7 @@ public sealed class IrregularNestingEngine : INestingEngine
             var reason = run.Reason;
             if (unplaced > 0 && reason == NestJobStopReason.Completed)
                 reason = NestJobStopReason.NoPlacementFound; // Demand no stock can hold.
-            return new Plan(run.Sheets, run.Net + unplaced * Penalty, unplaced, reason);
+            return new Plan(run.Sheets, NestJobCost.RequireFinite(run.Net + unplaced * Penalty), unplaced, reason, NestJobCost.UsesExplicitCosts(job));
         }
 
         /// <summary>
@@ -138,7 +138,7 @@ public sealed class IrregularNestingEngine : INestingEngine
                 var prefix = sheets.Take(sheets.Count - k).ToList();
                 var tail = sheets.Skip(sheets.Count - k).ToList();
                 var tailParts = tail.Sum(s => s.Parts.Count);
-                var tailNet = tail.Sum(s => NetArea(job.Options, s));
+                var tailNet = tail.Sum(s => NetCost(job.Options, s));
                 var tailDemand = new int[types.Count];
                 foreach (var part in tail.SelectMany(s => s.Parts))
                     tailDemand[part.Orientation.TypeIndex]++;
@@ -148,7 +148,7 @@ public sealed class IrregularNestingEngine : INestingEngine
                 int? cap = job.Options.MaxPlates is int max ? max - prefix.Count : null;
 
                 Run? bestRun = null;
-                var bestNet = tailNet - 1e-9 * System.Math.Max(1, tailNet);
+                var bestNet = tailNet - (NestJobCost.UsesExplicitCosts(job) ? 0 : 1e-9 * System.Math.Max(1, tailNet));
                 foreach (var (axis, beta) in Variants)
                     foreach (var first in job.Plates)
                     {
@@ -245,7 +245,7 @@ public sealed class IrregularNestingEngine : INestingEngine
                     var packer = new FrontierPacker(types, CacheFor(stock), PairsFor(stock), stock, axis, beta, Work, BlocksFor(stock));
                     var fill = packer.Fill(remaining, token);
                     if (fill.Parts.Count > 0)
-                        trials.Add((fill, NetArea(job.Options, fill)));
+                        trials.Add((fill, NetCost(job.Options, fill)));
                 }
 
                 if (trials.Count == 0)
@@ -260,14 +260,14 @@ public sealed class IrregularNestingEngine : INestingEngine
                 var remainingArea = types.Sum(t => remaining[t.Index] * t.Area);
                 var bestRatio = trials.Min(t => t.Net / System.Math.Max(t.Fill.PartArea, 1e-12));
                 var chosen = trials
-                    .Select((t, order) => (t.Fill, t.Net, order, Estimate: t.Net + System.Math.Max(0, remainingArea - t.Fill.PartArea) * bestRatio))
+                    .Select((t, order) => (t.Fill, t.Net, order, Estimate: NestJobCost.RequireFinite(t.Net + System.Math.Max(0, remainingArea - t.Fill.PartArea) * bestRatio)))
                     .OrderBy(t => t.Estimate)
                     .ThenByDescending(t => t.Fill.Parts.Count)
                     .ThenBy(t => t.order)
                     .First();
 
                 sheets.Add(chosen.Fill);
-                net += chosen.Net;
+                net = NestJobCost.RequireFinite(net + chosen.Net);
                 used[chosen.Fill.Stock.Id]++;
                 foreach (var part in chosen.Fill.Parts)
                     remaining[part.Orientation.TypeIndex]--;
@@ -289,21 +289,23 @@ public sealed class IrregularNestingEngine : INestingEngine
         return builder.Build(plan.Reason);
     }
 
-    private static double NetArea(NestJobOptions options, SheetFill fill)
+    private static double NetCost(NestJobOptions options, SheetFill fill)
     {
-        if (fill.Parts.Count == 0) return fill.Stock.Area;
+        if (fill.Parts.Count == 0) return NestJobCost.GrossSheetCost(fill.Stock);
         var left = fill.Parts.Min(p => p.Left);
         var bottom = fill.Parts.Min(p => p.Bottom);
-        return NestJobCost.NetSheetArea(options, fill.Stock, new OpenNest.Geometry.Box(left, bottom,
+        return NestJobCost.NetSheetCost(options, fill.Stock, new OpenNest.Geometry.Box(left, bottom,
             fill.Parts.Max(p => p.Right) - left, fill.Parts.Max(p => p.Top) - bottom));
     }
 
-    private sealed record Plan(IReadOnlyList<SheetFill> Sheets, double Cost, int Unplaced, NestJobStopReason Reason)
+    private sealed record Plan(IReadOnlyList<SheetFill> Sheets, double Cost, int Unplaced, NestJobStopReason Reason, bool Priced)
     {
         public bool IsBetterThan(Plan other)
         {
             if (Unplaced != other.Unplaced)
                 return Unplaced < other.Unplaced;
+            if (Priced && Cost != other.Cost)
+                return Cost < other.Cost;
             var scale = System.Math.Max(1, System.Math.Max(Cost, other.Cost));
             if (System.Math.Abs(Cost - other.Cost) > 1e-9 * scale)
                 return Cost < other.Cost;

OpenNest.Engine/NestingEngines/Rectangles/RectanglesNestingEngine.cs

@@ -18,8 +18,8 @@ namespace OpenNest.Engine.NestingEngines.Rectangles;
 ///
 /// Sheet by sheet, each available stock is packed under several free-space scoring rules and
 /// two pick modes (best-fitting box anywhere, or largest type first). The candidate sheet with
-/// the lowest estimated whole-job cost wins: its salvage-credited net area (NestJobCost) plus the
+/// the lowest estimated whole-job cost wins: its salvage-credited net cost (NestJobCost) plus the
-/// remaining demand priced at the best net-area-per-part-area ratio seen among the candidates.
+/// remaining demand priced at the best net-cost-per-part-area ratio seen among the candidates.
 /// Deterministic: no clocks or randomness; the only stop besides completion is the host token.
 /// </summary>
 public sealed class RectanglesNestingEngine : INestingEngine
@@ -78,7 +78,7 @@ public sealed class RectanglesNestingEngine : INestingEngine
                     {
                         var plan = SheetPacker.Pack(types, remaining, stock, rule, mode, token);
                         if (plan.Parts.Count > 0)
-                            trials.Add((plan, NetArea(job, plan)));
+                            trials.Add((plan, NetCost(job, plan)));
                     }
             }
 
@@ -101,7 +101,7 @@ public sealed class RectanglesNestingEngine : INestingEngine
 
     /// <summary>
     /// Picks the sheet with the lowest estimated whole-job cost. Remaining demand is priced at the
-    /// best net-area-per-material ratio any candidate achieved, so a sheet that finishes the job
+    /// best net-cost-per-material ratio any candidate achieved, so a sheet that finishes the job
     /// competes fairly with a denser partial one. Ties: more material placed, then enumeration order.
     /// </summary>
     private static SheetPlan Choose(
@@ -111,7 +111,7 @@ public sealed class RectanglesNestingEngine : INestingEngine
         var bestRatio = trials.Min(t => t.Net / System.Math.Max(t.Plan.MaterialArea, 1e-12));
         return trials
             .Select((t, order) => (t.Plan, order,
-                Estimate: t.Net + System.Math.Max(0, demandArea - t.Plan.MaterialArea) * bestRatio))
+                Estimate: NestJobCost.RequireFinite(t.Net + System.Math.Max(0, demandArea - t.Plan.MaterialArea) * bestRatio)))
             .OrderBy(t => PriorityDebt(types, remaining, t.Plan))
             .ThenBy(t => t.Estimate)
             .ThenByDescending(t => t.Plan.MaterialArea)
@@ -135,10 +135,10 @@ public sealed class RectanglesNestingEngine : INestingEngine
         return active.Where(t => t.Priority == top).Sum(t => remaining[t.Index]) - placed;
     }
 
-    private static double NetArea(NestJob job, SheetPlan plan) =>
+    private static double NetCost(NestJob job, SheetPlan plan) =>
         plan.Envelope is { } envelope
-            ? NestJobCost.NetSheetArea(job.Options, plan.Stock, envelope)
+            ? NestJobCost.NetSheetCost(job.Options, plan.Stock, envelope)
-            : plan.Stock.Area;
+            : NestJobCost.GrossSheetCost(plan.Stock);
 
     private static bool FitsStock(NestPlateStock stock, BoxOrientation o)
     {

OpenNest.FrontEnd.Tests/McpMixReportingTests.cs

@@ -0,0 +1,105 @@
+using OpenNest.CNC;
+using OpenNest.Engine.Jobs;
+using OpenNest.Geometry;
+using OpenNest.Mcp;
+using OpenNest.Mcp.Tools;
+
+namespace OpenNest.FrontEnd.Tests;
+
+[Collection("FrontEndRegistry")]
+public class McpMixReportingTests
+{
+    private static Drawing Rectangle(string name, double width, double length)
+    {
+        var shape = new Shape();
+        shape.Entities.Add(new Line(new Vector(0, 0), new Vector(width, 0)));
+        shape.Entities.Add(new Line(new Vector(width, 0), new Vector(width, length)));
+        shape.Entities.Add(new Line(new Vector(width, length), new Vector(0, length)));
+        shape.Entities.Add(new Line(new Vector(0, length), new Vector(0, 0)));
+        return new Drawing(name, OpenNest.Converters.ConvertGeometry.ToProgram(shape));
+    }
+
+    private static NestSession Session()
+    {
+        var session = new NestSession();
+        session.Drawings.Add(Rectangle("A", 2, 2));
+        session.Drawings.Add(Rectangle("B", 20, 20));
+        session.Plates.Add(new Plate(10, 10));
+        return session;
+    }
+
+    [Fact]
+    public void PackReportsZeroForUnfitDrawingAndCountsOnlyNewParts()
+    {
+        var session = Session();
+        var plate = session.GetPlate(0);
+        plate.Parts.Add(new Part(session.Drawings[0]));
+        var text = new NestingTools(session).PackPlate(0, "A,B", "10,10");
+        Assert.Contains("A: requested=10", text);
+        Assert.Contains("B: requested=10, placed=0, remaining=10", text);
+        Assert.Contains("remaining demand", text);
+        Assert.DoesNotContain("ratio not met", text);
+        Assert.Contains($"A: requested=10, placed={plate.Parts.Count - 1}, remaining={11 - plate.Parts.Count}", text);
+        Assert.True(plate.Parts.Count > 1);
+    }
+
+    [Fact]
+    public void AutoNestReportsSkewedAndZeroProgressByRequirement()
+    {
+        var session = Session();
+        var engine = "MixStub-" + Guid.NewGuid();
+        NestingEngineRegistry.Register(engine, "test", () => new Stub());
+        var tool = new NestingTools(session);
+        var text = tool.AutoNestPlate(0, "A,B", "2,2", engine);
+        Assert.Contains("A: requested=2, placed=1, remaining=1", text);
+        Assert.Contains("B: requested=2, placed=0, remaining=2", text);
+        Assert.Contains("remaining demand", text);
+        Assert.DoesNotContain("ratio not met", text);
+
+        // Duplicate tokens must be refused before the engine can mutate a fresh target.
+        var fresh = Session();
+        Assert.Contains("duplicate", new NestingTools(fresh).AutoNestPlate(0, "A,A", "2,2", engine), StringComparison.OrdinalIgnoreCase);
+        Assert.Empty(fresh.GetPlate(0).Parts);
+        Assert.Single(session.GetPlate(0).Parts);
+    }
+
+    [Fact]
+    public void PackZeroProgressAndAmbiguousNamesAreExplicit()
+    {
+        var session = Session();
+        session.GetPlate(0).Size = new Size(1, 1);
+        var text = new NestingTools(session).PackPlate(0, "A,B", "2,2");
+        Assert.Contains("A: requested=2, placed=0, remaining=2", text);
+        Assert.Contains("B: requested=2, placed=0, remaining=2", text);
+        Assert.Contains("zero progress", text);
+        Assert.Empty(session.GetPlate(0).Parts);
+
+        session.Drawings.Add(Rectangle("A", 1, 1));
+        Assert.Contains("ambiguous drawing name", new NestingTools(session).PackPlate(0, "A,B", "2,2"));
+        Assert.Empty(session.GetPlate(0).Parts);
+    }
+
+    [Fact]
+    public void ZeroDemandHasZeroRemainingAndNegativeDemandIsRejected()
+    {
+        var session = Session();
+        var tools = new NestingTools(session);
+        var text = tools.PackPlate(0, "A", "0");
+        Assert.Contains("A: requested=0, placed=0, remaining=0", text);
+        Assert.Contains("zero progress", text);
+        Assert.Contains("negative", tools.PackPlate(0, "A", "-1"), StringComparison.OrdinalIgnoreCase);
+        Assert.Empty(session.GetPlate(0).Parts);
+    }
+
+    private sealed class Stub : INestingEngine
+    {
+        public NestJobResult Solve(NestJob job, IProgress<NestJobProgress>? progress = null,
+            CancellationToken token = default)
+        {
+            var placed = new[] { new NestJobPlacement(job.Parts[0].Id, 0, 1, 1, 0) };
+            return new NestJobResult(NestJobStatus.Incomplete, NestJobStopReason.Completed,
+                [new NestJobPlateResult(0, job.Plates[0], placed)],
+                [], []);
+        }
+    }
+}

OpenNest.FrontEnd.Tests/McpPlateToolsTests.cs

@@ -0,0 +1,112 @@
+using OpenNest.CNC;
+using OpenNest.Geometry;
+using OpenNest.IO;
+using OpenNest.Mcp;
+using OpenNest.Mcp.Tools;
+
+namespace OpenNest.FrontEnd.Tests;
+
+public class McpPlateToolsTests : IDisposable
+{
+    private readonly string directory = Path.Combine(Path.GetTempPath(), "opennest-mcp-plates-" + Guid.NewGuid());
+
+    public McpPlateToolsTests() => Directory.CreateDirectory(directory);
+    public void Dispose() => Directory.Delete(directory, true);
+
+    [Fact]
+    public void NegativeIndexOnLoadedNestIsNotAPlate()
+    {
+        var session = new NestSession { Nest = new Nest() };
+        var loaded = new Plate(10, 20);
+        session.Nest.Plates.Add(loaded);
+        var appended = new Plate(30, 40);
+        session.Plates.Add(appended);
+
+        Assert.Null(session.GetPlate(-1));
+        Assert.Equal("Error: plate -1 not found", new SetupTools(session).ClearPlate(-1));
+        Assert.Same(loaded, session.GetPlate(0));
+        Assert.Same(appended, session.GetPlate(1));
+        Assert.Null(session.GetPlate(2));
+        Assert.Single(session.Nest.Plates);
+        Assert.Single(session.Plates);
+
+        var sessionOnly = new NestSession();
+        sessionOnly.Plates.Add(appended);
+        Assert.Null(sessionOnly.GetPlate(-1));
+        Assert.Same(appended, sessionOnly.GetPlate(0));
+        Assert.Null(sessionOnly.GetPlate(1));
+    }
+
+    private static string Delete(SetupTools tools, int index) => tools.DeletePlate(index);
+
+    [Fact]
+    public void DeleteEmptyLoadedMiddlePlateRenumbersAppendedAndPersists()
+    {
+        var session = new NestSession { Nest = new Nest("fixture") };
+        var drawing = new Drawing("square", new Program());
+        session.Nest.Drawings.Add(drawing);
+        var occupied = new Plate(20, 30) { Quantity = 2 };
+        occupied.Parts.Add(new Part(drawing));
+        var unused = new Plate(40, 50);
+        var appended = new Plate(60, 70) { PartSpacing = 1.25, Quantity = 3 };
+        session.Nest.Plates.Add(occupied);
+        session.Nest.Plates.Add(unused);
+        session.Plates.Add(appended);
+        var tools = new SetupTools(session);
+
+        var result = Delete(tools, 1);
+        Assert.Contains("Deleted plate 1", result);
+        Assert.Contains("2 -> 1", result);
+        Assert.Single(session.Nest.Plates);
+        Assert.Same(appended, session.GetPlate(1));
+        Assert.Null(session.GetPlate(2));
+        Assert.Contains("60.0 x 70.0", new InspectionTools(session).GetPlateInfo(1));
+        Assert.Equal(2, drawing.Quantity.Nested);
+
+        var path = Path.Combine(directory, "cleaned.nest");
+        Assert.Contains("Saved nest", new InputTools(session).SaveNest(path));
+        var reloaded = new NestReader(path).Read();
+        // NestWriter already omits empty plates; the deletion is session cleanup,
+        // and the saved file must still retain the occupied plate and its counts.
+        var saved = Assert.Single(reloaded.Plates);
+        Assert.Single(saved.Parts);
+        Assert.Equal(20, saved.Size.Width);
+        Assert.Equal(2, saved.Quantity);
+        Assert.Equal(2, reloaded.Drawings.Single().Quantity.Nested);
+    }
+
+    [Fact]
+    public void DeleteRefusesOccupiedCutoffAndInvalidIndicesWithoutMutation()
+    {
+        var session = new NestSession { Nest = new Nest("fixture") };
+        var drawing = new Drawing("square", new Program());
+        session.Nest.Drawings.Add(drawing);
+        var occupied = new Plate(20, 30) { Quantity = 4 };
+        var part = new Part(drawing);
+        occupied.Parts.Add(part);
+        var cutoff = new Plate(40, 50);
+        var definition = new CutOff(new Vector(10, 10), CutOffAxis.Vertical);
+        cutoff.CutOffs.Add(definition);
+        session.Nest.Plates.Add(occupied);
+        session.Plates.Add(cutoff);
+        var tools = new SetupTools(session);
+
+        Assert.Contains("occupied", Delete(tools, 0));
+        Assert.Contains("cutoff", Delete(tools, 1), StringComparison.OrdinalIgnoreCase);
+        Assert.Contains("not found", Delete(tools, -1));
+        Assert.Contains("not found", Delete(tools, 2));
+        Assert.Same(occupied, session.GetPlate(0));
+        Assert.Same(cutoff, session.GetPlate(1));
+        Assert.Same(part, Assert.Single(occupied.Parts));
+        Assert.Same(definition, Assert.Single(cutoff.CutOffs));
+        Assert.Equal(4, drawing.Quantity.Nested);
+        Assert.Single(session.Nest.Plates);
+        Assert.Single(session.Plates);
+
+        // The session-only collection must also delete without requiring a loaded nest.
+        var standalone = new NestSession();
+        standalone.Plates.Add(new Plate(12, 13));
+        Assert.Contains("Deleted plate 0", Delete(new SetupTools(standalone), 0));
+        Assert.Empty(standalone.Plates);
+    }
+}

OpenNest.FrontEnd.Tests/McpWholeJobTests.cs

@@ -0,0 +1,506 @@
+using OpenNest.CNC;
+using OpenNest.CNC.CuttingStrategy;
+using OpenNest.Engine.Jobs;
+using OpenNest.Geometry;
+using OpenNest.IO;
+using OpenNest.Mcp;
+using OpenNest.Mcp.Tools;
+
+namespace OpenNest.FrontEnd.Tests;
+
+[Collection("FrontEndRegistry")]
+public class McpWholeJobTests : IDisposable
+{
+    private readonly string directory = Path.Combine(Path.GetTempPath(), "opennest-mcp-job-" + Guid.NewGuid());
+    public McpWholeJobTests() => Directory.CreateDirectory(directory);
+    public void Dispose() => Directory.Delete(directory, true);
+
+    private static Drawing Square(string name, double size = 2)
+    {
+        var shape = new Shape();
+        shape.Entities.Add(new Line(new Vector(0, 0), new Vector(size, 0)));
+        shape.Entities.Add(new Line(new Vector(size, 0), new Vector(size, size)));
+        shape.Entities.Add(new Line(new Vector(size, size), new Vector(0, size)));
+        shape.Entities.Add(new Line(new Vector(0, size), new Vector(0, 0)));
+        return new Drawing(name, OpenNest.Converters.ConvertGeometry.ToProgram(shape));
+    }
+
+    private static NestSession Session()
+    {
+        var session = new NestSession { Nest = new Nest("job") };
+        session.Nest.Drawings.Add(Square("A"));
+        session.Nest.Drawings.Add(Square("B"));
+        session.Nest.Plates.Add(new Plate(10, 10) { PartSpacing = 0.25, Quantity = 1 });
+        return session;
+    }
+
+    private static string Call(NestingTools tools, int plateIndex, string names, string quantities,
+        string engine, bool noNew = false, CancellationToken token = default) =>
+        tools.AutoNestJob(plateIndex, names, quantities, engine, noNew, token);
+
+    [Fact]
+    public void AcceptedPricesAndRequirementsSurviveSaveWithoutLosingMetadata()
+    {
+        var session = Session();
+        session.Nest.Customer = "Cost customer";
+        session.Nest.Notes = "Keep these notes";
+        session.Nest.Units = Units.Inches;
+        session.Nest.SalvageRate = 0.25;
+        var output = new NestingTools(session).AutoNestJob(0, "A,B", "1,1", "Rectangles", sheets:
+            [new SheetStockInput { Width = 10, Length = 10, Quantity = 2, Cost = 50 },
+             new SheetStockInput { Width = 12, Length = 12, Quantity = 2, Cost = 7 }]);
+        Assert.Contains("Whole job complete", output);
+        Assert.Contains("gross total=7", output);
+        Assert.Contains("net score=7", output);
+        Assert.Contains("supplied-cost", output);
+        Assert.All(session.AllDrawings(), d => Assert.Equal(1, d.Quantity.Required));
+        var path = Path.Combine(directory, "priced.nest");
+        new InputTools(session).SaveNest(path);
+        var reopened = new NestReader(path).Read();
+        Assert.Equal("Cost customer", reopened.Customer);
+        Assert.Equal("Keep these notes", reopened.Notes);
+        Assert.Equal(Units.Inches, reopened.Units);
+        Assert.Equal(0.25, reopened.SalvageRate);
+        Assert.Equal(new[] { 50d, 7d }, reopened.PlateOptions.Select(o => o.Cost));
+        Assert.All(reopened.Drawings, d => Assert.Equal(1, d.Quantity.Required));
+        Assert.Equal(2, reopened.Plates.Sum(p => p.Parts.Count));
+    }
+
+    [Theory]
+    [InlineData(null)]
+    [InlineData(0d)]
+    [InlineData(-1d)]
+    [InlineData(double.NaN)]
+    [InlineData(double.PositiveInfinity)]
+    public void InvalidCostsDoNotMutateSession(double? cost)
+    {
+        var session = Session();
+        var quantities = session.AllDrawings().Select(d => d.Quantity.Required).ToArray();
+        var output = new NestingTools(session).AutoNestJob(0, "A,B", "1,1", "Rectangles", sheets:
+            [new SheetStockInput { Width = 10, Length = 10, Quantity = 1, Cost = 5 },
+             new SheetStockInput { Width = 12, Length = 12, Quantity = 1, Cost = cost }]);
+        Assert.Contains("Error:", output);
+        Assert.Contains("sheets[1]", output);
+        Assert.Empty(session.GetPlate(0).Parts);
+        Assert.Empty(session.Nest.PlateOptions);
+        Assert.Equal(quantities, session.AllDrawings().Select(d => d.Quantity.Required));
+    }
+
+    [Fact]
+    public void FiniteSheetInputsReachEngineWithTemplateSettings()
+    {
+        var session = Session();
+        var template = session.GetPlate(0);
+        template.Size = new Size(60, 120);
+        template.EdgeSpacing = new Spacing(1, 2, 3, 4);
+        template.Quadrant = 3;
+        var engine = "StockMap-" + Guid.NewGuid();
+        var called = false;
+        NestingEngineRegistry.Register(engine, "inspect finite stock", () => new InspectStub(job =>
+        {
+            called = true;
+            Assert.Equal(2, job.Plates.Count);
+            Assert.Equal(["stock-0", "stock-1"], job.Plates.Select(s => s.Id));
+            Assert.Equal([new Size(60, 120), new Size(48, 96)], job.Plates.Select(s => s.Size));
+            Assert.Equal([1, 2], job.Plates.Select(s => s.Quantity));
+            Assert.All(job.Plates, stock =>
+            {
+                Assert.Equal(0.25, stock.PartSpacing);
+                Assert.Equal(template.EdgeSpacing, stock.EdgeSpacing);
+                Assert.Equal(3, stock.Quadrant);
+            });
+            Assert.Equal(2, job.Options.MaxPlates); // capped by demand, not plate.Quantity
+            return new NestJobResult(NestJobStatus.Incomplete, NestJobStopReason.StockExhausted, [], [], []);
+        }));
+        var rows = new[] { new SheetStockInput { Width = 60, Length = 120, Quantity = 1 },
+            new SheetStockInput { Width = 48, Length = 96, Quantity = 2 } };
+        var tool = new NestingTools(session);
+        Assert.Contains("incomplete", tool.AutoNestJob(0, "A,B", "1,1", engine, sheets: rows));
+        Assert.True(called);
+        called = false;
+        rows[1].Width = double.NaN;
+        Assert.Contains("sheets[1]", tool.AutoNestJob(0, "A,B", "1,1", engine, sheets: rows));
+        Assert.False(called);
+        Assert.Single(session.AllPlates());
+        Assert.Empty(template.Parts);
+        Assert.Equal(1, template.Quantity); // no inventory drawn from the template quantity
+    }
+
+    private sealed class InspectStub(Func<NestJob, NestJobResult> solve) : INestingEngine
+    {
+        public NestJobResult Solve(NestJob job, IProgress<NestJobProgress>? progress = null,
+            CancellationToken token = default) => solve(job);
+    }
+
+    [Fact]
+    public void FiniteMixedSheetsCommitByStockIdAndRoundTrip()
+    {
+        var session = Session();
+        var template = session.GetPlate(0);
+        template.Size = new Size(6, 6);
+        template.Quantity = 9; // repeat count is not inventory
+        var small = session.Nest.Drawings.Single(d => d.Name == "B");
+        var large = Square("large", 4); // four-by-four cannot fit a three-by-three sheet
+        session.Nest.Drawings.Add(large);
+        var rows = new[] { new SheetStockInput { Width = 6, Length = 6, Quantity = 1 },
+            new SheetStockInput { Width = 3, Length = 3, Quantity = 2 } };
+        var engine = "MixedStock-" + Guid.NewGuid();
+        NestingEngineRegistry.Register(engine, "two different sheets", () => new InspectStub(job =>
+        {
+            Assert.Equal(2, job.Options.MaxPlates);
+            Assert.Equal([1, 2], job.Plates.Select(s => s.Quantity));
+            // Small stock first: result ordinal must not resize/reuse the large template.
+            return new NestJobResult(NestJobStatus.Complete, NestJobStopReason.Completed,
+                [new NestJobPlateResult(0, job.Plates[1], [new NestJobPlacement(job.Parts[1].Id, 0, 0.5, 0.5, 0)]),
+                 new NestJobPlateResult(1, job.Plates[0], [new NestJobPlacement(job.Parts[0].Id, 1, 0.5, 0.5, 0)])], [], []);
+        }));
+        var text = new NestingTools(session).AutoNestJob(0, "large,B", "1,1", engine, sheets: rows);
+        Assert.Contains("Whole job complete", text);
+        Assert.Contains("stock-0 (6x6): used=1, remaining=0, reused=1, created=0", text);
+        Assert.Contains("stock-1 (3x3): used=1, remaining=1, reused=0, created=1", text);
+        Assert.Contains("plate 0 -> stock-0", text);
+        Assert.Contains("plate 1 -> stock-1", text);
+        Assert.Same(template, session.GetPlate(0));
+        Assert.Equal(new Size(6, 6), template.Size);
+        Assert.Same(large, Assert.Single(template.Parts).BaseDrawing);
+        Assert.Same(small, Assert.Single(session.GetPlate(1).Parts).BaseDrawing);
+        Assert.Equal(1, template.Quantity);
+        var path = Path.Combine(directory, "mixed.nest");
+        Assert.Contains("Saved nest", new InputTools(session).SaveNest(path));
+        var reloaded = new NestReader(path).Read();
+        Assert.Equal([new Size(6, 6), new Size(3, 3)], reloaded.Plates.Select(p => p.Size));
+        Assert.All(reloaded.Plates, p => Assert.Equal(1, p.Quantity));
+        Assert.Equal(1, reloaded.Drawings.Single(d => d.Name == "large").Quantity.Nested);
+        Assert.Equal(1, reloaded.Drawings.Single(d => d.Name == "B").Quantity.Nested);
+    }
+
+    [Fact]
+    public void FiniteStockOverdrawIsRejectedBeforeAnySessionMutation()
+    {
+        var session = Session();
+        var plate = session.GetPlate(0);
+        plate.Size = new Size(3, 3);
+        var engine = "Overdraw-" + Guid.NewGuid();
+        NestingEngineRegistry.Register(engine, "overdraw stock", () => new InspectStub(job =>
+            new NestJobResult(NestJobStatus.Complete, NestJobStopReason.Completed,
+                [new NestJobPlateResult(0, job.Plates[0], [new NestJobPlacement(job.Parts[0].Id, 0, 0.5, 0.5, 0)]),
+                 new NestJobPlateResult(1, job.Plates[0], [new NestJobPlacement(job.Parts[1].Id, 1, 0.5, 0.5, 0)])], [], [])));
+        var text = new NestingTools(session).AutoNestJob(0, "A,B", "1,1", engine,
+            sheets: [new SheetStockInput { Width = 3, Length = 3, Quantity = 1 },
+                new SheetStockInput { Width = 6, Length = 6, Quantity = 2 }]);
+        Assert.Contains("stock-0", text);
+        Assert.Contains("invalid", text, StringComparison.OrdinalIgnoreCase);
+        Assert.Single(session.AllPlates());
+        Assert.Empty(plate.Parts);
+        Assert.All(session.Nest.Drawings, d => Assert.Equal(0, d.Quantity.Nested));
+    }
+
+    [Fact]
+    public void FiniteStockRejectsInvalidInventoryBeforeSolving()
+    {
+        var session = Session();
+        var plate = session.GetPlate(0);
+        var engine = "NeverSolve-" + Guid.NewGuid();
+        NestingEngineRegistry.Register(engine, "should not be called", () => new InspectStub(_ =>
+            throw new Xunit.Sdk.XunitException("invalid input reached solver")));
+        var tools = new NestingTools(session);
+        var valid = new SheetStockInput { Width = 10, Length = 10, Quantity = 1 };
+        Assert.Contains("at least one", tools.AutoNestJob(0, "A", "1", engine, sheets: []));
+        Assert.Contains("sheets[0]", tools.AutoNestJob(0, "A", "1", engine,
+            sheets: [new SheetStockInput { Width = 10, Length = 10, Quantity = 0 }]));
+        Assert.Contains("sheets[0]", tools.AutoNestJob(0, "A", "1", engine,
+            sheets: [new SheetStockInput { Width = double.PositiveInfinity, Length = 10, Quantity = 1 }]));
+        Assert.Contains("sheets[0]", tools.AutoNestJob(0, "A", "1", engine,
+            sheets: [new SheetStockInput { Width = 0, Length = 10, Quantity = 1 }]));
+        Assert.Contains("sheets[1] duplicates sheets[0]", tools.AutoNestJob(0, "A", "1", engine,
+            sheets: [valid, new SheetStockInput { Width = 10, Length = 10, Quantity = 2 }]));
+        Assert.Contains("sheet inventory exceeds", tools.AutoNestJob(0, "A", "1", engine,
+            sheets: [new SheetStockInput { Width = 10, Length = 10, Quantity = int.MaxValue },
+                new SheetStockInput { Width = 11, Length = 11, Quantity = 1 }]));
+        Assert.Contains("cannot be combined", tools.AutoNestJob(0, "A", "1", engine,
+            no_new_plates: true, sheets: [valid]));
+        Assert.Single(session.AllPlates());
+        Assert.Empty(plate.Parts);
+        Assert.Equal(1, plate.Quantity);
+    }
+
+    [Fact]
+    public void FiniteInventoryUsesOnlyOneOfTwoMatchingEmptySheets()
+    {
+        var session = Session();
+        var original = session.GetPlate(0);
+        session.Plates.Add(new Plate(10, 10) { PartSpacing = 0.25, Quantity = 5 });
+        var text = new NestingTools(session).AutoNestJob(0, "A", "1", "Rectangles",
+            sheets: [new SheetStockInput { Width = 10, Length = 10, Quantity = 1 }]);
+        Assert.Contains("Whole job complete", text);
+        Assert.Contains("stock-0 (10x10): used=1, remaining=0", text);
+        Assert.Single(original.Parts);
+        Assert.Empty(session.GetPlate(1).Parts);
+        Assert.Equal(5, session.GetPlate(1).Quantity);
+    }
+
+    [Fact]
+    public void LaterSelectedTemplateIsReusedBeforeOtherCompatibleEmptySheet()
+    {
+        var session = Session();
+        var earlier = session.GetPlate(0);
+        var selected = new Plate(10, 10) { PartSpacing = 0.25, Quantity = 3 };
+        session.Plates.Add(selected);
+        var text = new NestingTools(session).AutoNestJob(1, "A", "1", "Rectangles");
+        Assert.Contains("Whole job complete", text);
+        Assert.Empty(earlier.Parts);
+        Assert.Single(selected.Parts);
+        Assert.Equal(1, selected.Quantity);
+    }
+
+    [Fact]
+    public void CreatesSheetsForCompleteMixedJobThenSavesAndReloads()
+    {
+        var session = Session();
+        var original = session.GetPlate(0);
+        var engine = "JobTwoSheets-" + Guid.NewGuid();
+        NestingEngineRegistry.Register(engine, "two safe sheets", () => new TwoSheetStub());
+        var text = Call(new NestingTools(session), 0, "A,B", "2,2", engine);
+        Assert.Contains("complete", text, StringComparison.OrdinalIgnoreCase);
+        Assert.Equal(2, session.AllPlates().Count);
+        Assert.Same(original, session.GetPlate(0));
+        Assert.Single(session.Plates);
+        Assert.All(session.AllPlates(), plate =>
+        {
+            Assert.Equal(2, plate.Parts.Count);
+            Assert.Equal(0.25, plate.PartSpacing);
+            Assert.Equal(1, plate.Quantity);
+        });
+        Assert.Equal(2, session.Nest.Drawings.Single(d => d.Name == "A").Quantity.Nested);
+        Assert.Equal(2, session.Nest.Drawings.Single(d => d.Name == "B").Quantity.Nested);
+        var path = Path.Combine(directory, "complete.nest");
+        Assert.Contains("Saved nest", new InputTools(session).SaveNest(path));
+        var loaded = new NestReader(path).Read();
+        Assert.Equal(2, loaded.Plates.Count);
+        Assert.Equal(2, loaded.Drawings.Single(d => d.Name == "A").Quantity.Nested);
+        Assert.Equal(2, loaded.Drawings.Single(d => d.Name == "B").Quantity.Nested);
+    }
+
+    [Fact]
+    public void NoNewPlateFlagRefusesIncompleteProposalWithoutMutation()
+    {
+        var session = Session();
+        var original = session.GetPlate(0);
+        var engine = "JobLimited-" + Guid.NewGuid();
+        NestingEngineRegistry.Register(engine, "one sheet when capped", () => new TwoSheetStub());
+        var text = Call(new NestingTools(session), 0, "A,B", "2,2", engine, noNew: true);
+        Assert.Contains("incomplete", text, StringComparison.OrdinalIgnoreCase);
+        Assert.Contains("Nothing committed", text);
+        Assert.Single(session.AllPlates());
+        Assert.Same(original, session.GetPlate(0));
+        Assert.Empty(original.Parts);
+        Assert.All(session.Nest.Drawings, d => Assert.Equal(0, d.Quantity.Nested));
+    }
+
+    [Fact]
+    public void ExistingQuantityAndPrecreatedSheetsCompleteWithRealEngine()
+    {
+        var session = Session();
+        var occupied = session.GetPlate(0);
+        occupied.Quantity = 2;
+        occupied.Parts.Add(new Part(session.Nest.Drawings.Single(d => d.Name == "A")));
+        var first = new Plate(3, 3) { PartSpacing = 0.25, Quantity = 1 };
+        var second = new Plate(3, 3) { PartSpacing = 0.25, Quantity = 1 };
+        session.Plates.Add(first);
+        session.Plates.Add(second);
+        var text = Call(new NestingTools(session), 1, "A,B", "3,1", "Rectangles", noNew: true);
+        Assert.Contains("Whole job complete", text);
+        Assert.Contains("0 new sheet(s)", text);
+        Assert.Same(first, session.GetPlate(1));
+        Assert.Same(second, session.GetPlate(2));
+        Assert.Equal(3, session.Nest.Drawings.Single(d => d.Name == "A").Quantity.Nested);
+        Assert.Equal(1, session.Nest.Drawings.Single(d => d.Name == "B").Quantity.Nested);
+        Assert.Equal(3, session.AllPlates().Count);
+        var path = Path.Combine(directory, "existing.nest");
+        Assert.Contains("Saved nest", new InputTools(session).SaveNest(path));
+        var loaded = new NestReader(path).Read();
+        Assert.Equal(3, loaded.Plates.Count);
+        Assert.Equal(3, loaded.Drawings.Single(d => d.Name == "A").Quantity.Nested);
+        Assert.Equal(1, loaded.Drawings.Single(d => d.Name == "B").Quantity.Nested);
+    }
+
+    [Fact]
+    public void RealEngineAddsSheetsWhenOnlyTemplateExists()
+    {
+        var session = Session();
+        session.GetPlate(0).Size = new Size(3, 3);
+        var text = Call(new NestingTools(session), 0, "A,B", "2,2", "Rectangles");
+        Assert.Contains("Whole job complete", text);
+        Assert.Equal(4, session.AllPlates().Count);
+        Assert.All(session.AllPlates(), p => Assert.Single(p.Parts));
+        Assert.Equal(2, session.Nest.Drawings.Single(d => d.Name == "A").Quantity.Nested);
+        Assert.Equal(2, session.Nest.Drawings.Single(d => d.Name == "B").Quantity.Nested);
+    }
+
+    [Fact]
+    public void InvalidPluginLayoutCannotCreateOrOccupySheets()
+    {
+        var session = Session();
+        var original = session.GetPlate(0);
+        var engine = "JobOverlap-" + Guid.NewGuid();
+        NestingEngineRegistry.Register(engine, "invalid layout", () => new TwoSheetStub(overlap: true));
+        var text = Call(new NestingTools(session), 0, "A,B", "2,2", engine);
+        Assert.Contains("invalid", text, StringComparison.OrdinalIgnoreCase);
+        Assert.Contains("Nothing committed", text);
+        Assert.Single(session.AllPlates());
+        Assert.Same(original, session.GetPlate(0));
+        Assert.Empty(original.Parts);
+        Assert.All(session.Nest.Drawings, d => Assert.Equal(0, d.Quantity.Nested));
+    }
+
+    [Fact]
+    public void RestrictedDrawingRejectsPluginRotationWithoutMutationAfterReload()
+    {
+        var session = Session();
+        var drawing = session.Nest.Drawings.Single(d => d.Name == "A");
+        drawing.Constraints = new NestConstraints
+        {
+            StepAngle = OpenNest.Math.Angle.TwoPI,
+            StartAngle = 0,
+            EndAngle = 0,
+        };
+        session.GetPlate(0).Parts.Add(new Part(session.Nest.Drawings.Single(d => d.Name == "B")));
+        var path = Path.Combine(directory, "rotation.nest");
+        Assert.True(new NestWriter(session.Nest).Write(path));
+        session = new NestSession { Nest = new NestReader(path).Read() };
+        Assert.Equal(OpenNest.Math.Angle.TwoPI, session.Nest.Drawings.Single(d => d.Name == "A").Constraints.StepAngle);
+        session.Plates.Add(new Plate(10, 10) { PartSpacing = 0.25, Quantity = 1 });
+        var engine = "JobForbiddenRotation-" + Guid.NewGuid();
+        NestingEngineRegistry.Register(engine, "rotated proposal", () => new RotatedStub());
+        var plateTool = new NestingTools(session).AutoNestPlate(1, "A", "1", engine);
+        Assert.Contains("Violation", plateTool);
+        Assert.Contains("rotation", plateTool, StringComparison.OrdinalIgnoreCase);
+        Assert.Empty(session.GetPlate(1).Parts);
+        var text = Call(new NestingTools(session), 1, "A", "1", engine);
+        Assert.True(text.Contains("rotation", StringComparison.OrdinalIgnoreCase), text);
+        Assert.Contains("Nothing committed", text);
+        Assert.Equal(2, session.AllPlates().Count);
+        Assert.Empty(session.GetPlate(1).Parts);
+        Assert.Single(session.GetPlate(0).Parts);
+        Assert.Equal(0, session.Nest.Drawings.Single(d => d.Name == "A").Quantity.Nested);
+    }
+
+    [Fact]
+    public void EquivalentDeserializedCuttingSettingsReuseExistingSheets()
+    {
+        var session = Session();
+        var first = session.GetPlate(0);
+        first.Size = new Size(3, 3);
+        first.CuttingParameters = new CuttingParameters { MachineName = "Same" };
+        var second = new Plate(3, 3)
+        {
+            Quantity = 1,
+            PartSpacing = 0.25,
+            CuttingParameters = new CuttingParameters { MachineName = "Same" }
+        };
+        session.Plates.Add(second);
+        Assert.NotSame(first.CuttingParameters, second.CuttingParameters);
+        var text = Call(new NestingTools(session), 0, "A", "2", "Rectangles", noNew: true);
+        Assert.Contains("Whole job complete", text);
+        Assert.Equal(2, session.AllPlates().Count);
+        Assert.Single(first.Parts);
+        Assert.Single(second.Parts);
+    }
+
+    [Fact]
+    public void DifferentCuttingSettingsAreNotReusedAsStock()
+    {
+        var session = Session();
+        var first = session.GetPlate(0);
+        first.Size = new Size(3, 3);
+        first.CuttingParameters = new CuttingParameters { MachineName = "First" };
+        var second = new Plate(3, 3)
+        {
+            Quantity = 1,
+            PartSpacing = 0.25,
+            CuttingParameters = new CuttingParameters { MachineName = "Other" }
+        };
+        session.Plates.Add(second);
+        var text = Call(new NestingTools(session), 0, "A", "2", "Rectangles", noNew: true);
+        Assert.Contains("incomplete", text, StringComparison.OrdinalIgnoreCase);
+        Assert.Contains("Nothing committed", text);
+        Assert.Empty(first.Parts);
+        Assert.Empty(second.Parts);
+        Assert.Equal(2, session.AllPlates().Count);
+    }
+
+    [Fact]
+    public void SolverNotSupportedErrorNamesActualCause()
+    {
+        var session = Session();
+        var engine = "JobUnsupported-" + Guid.NewGuid();
+        NestingEngineRegistry.Register(engine, "unsupported solver", () => new UnsupportedStub());
+        var text = Call(new NestingTools(session), 0, "A", "1", engine);
+        Assert.Contains("unsupported fixture", text);
+        Assert.DoesNotContain("Use autonest_plate", text);
+        Assert.Contains("Nothing committed", text);
+        Assert.Empty(session.GetPlate(0).Parts);
+    }
+
+    [Fact]
+    public void CancellationAfterPluginIgnoresTokenDoesNotCommit()
+    {
+        var session = Session();
+        var required = session.AllDrawings().Select(d => d.Quantity.Required).ToArray();
+        using var cts = new CancellationTokenSource();
+        var engine = "JobCancel-" + Guid.NewGuid();
+        NestingEngineRegistry.Register(engine, "cancels after solving", () => new CancelStub(cts));
+        Assert.ThrowsAny<OperationCanceledException>(() =>
+            Call(new NestingTools(session), 0, "A,B", "2,2", engine, token: cts.Token));
+        Assert.Single(session.AllPlates());
+        Assert.Empty(session.GetPlate(0).Parts);
+        Assert.All(session.Nest.Drawings, d => Assert.Equal(0, d.Quantity.Nested));
+        Assert.Equal(required, session.AllDrawings().Select(d => d.Quantity.Required));
+    }
+
+    private sealed class CancelStub(CancellationTokenSource source) : INestingEngine
+    {
+        public NestJobResult Solve(NestJob job, IProgress<NestJobProgress>? progress = null,
+            CancellationToken token = default)
+        {
+            var result = new TwoSheetStub().Solve(job, progress, token);
+            source.Cancel();
+            return result;
+        }
+    }
+
+    private sealed class RotatedStub : INestingEngine
+    {
+        public NestJobResult Solve(NestJob job, IProgress<NestJobProgress>? progress = null,
+            CancellationToken token = default)
+        {
+            var stock = Assert.Single(job.Plates);
+            return new NestJobResult(NestJobStatus.Complete, NestJobStopReason.Completed,
+                [new NestJobPlateResult(0, stock,
+                    [new NestJobPlacement(job.Parts[0].Id, 0, 4, 4, System.Math.PI / 2)])], [], []);
+        }
+    }
+
+    private sealed class UnsupportedStub : INestingEngine
+    {
+        public NestJobResult Solve(NestJob job, IProgress<NestJobProgress>? progress = null,
+            CancellationToken token = default) => throw new NotSupportedException("unsupported fixture");
+    }
+
+    private sealed class TwoSheetStub(bool overlap = false) : INestingEngine
+    {
+        public NestJobResult Solve(NestJob job, IProgress<NestJobProgress>? progress = null,
+            CancellationToken token = default)
+        {
+            var stock = Assert.Single(job.Plates);
+            var sheets = new List<NestJobPlateResult>();
+            for (var i = 0; i < System.Math.Min(2, stock.Quantity ?? 2); i++)
+                sheets.Add(new NestJobPlateResult(i, stock,
+                [new NestJobPlacement(job.Parts[0].Id, i, 1, 1, 0),
+                 new NestJobPlacement(job.Parts[1].Id, i, overlap ? 1 : 5, 1, 0)]));
+            return new NestJobResult(sheets.Count == 2 ? NestJobStatus.Complete : NestJobStatus.Incomplete,
+                sheets.Count == 2 ? NestJobStopReason.Completed : NestJobStopReason.StockExhausted,
+                sheets, [], []);
+        }
+    }
+}

OpenNest.IO.Tests/StockCostPersistenceTests.cs

@@ -0,0 +1,32 @@
+using OpenNest.Engine.Jobs;
+using OpenNest.IO;
+
+namespace OpenNest.IO.Tests;
+
+public class StockCostPersistenceTests
+{
+    [Theory]
+    [InlineData(0)]
+    [InlineData(12.5)]
+    public void ExistingOptionsRoundTripWithoutChangingMetadata(double cost)
+    {
+        var nest = new Nest("priced options")
+        {
+            Customer = "customer",
+            Notes = "notes",
+            Units = Units.Inches,
+            SalvageRate = 0.25,
+            PlateOptions = [new PlateOption { Width = 48, Length = 96, Cost = cost }],
+        };
+        using var stream = new MemoryStream();
+        Assert.True(new NestWriter(nest).Write(stream));
+        stream.Position = 0;
+        var reopened = new NestReader(stream).Read();
+        Assert.Equal(cost, Assert.Single(reopened.PlateOptions).Cost);
+        Assert.Equal(nest.Customer, reopened.Customer);
+        Assert.Equal(nest.Notes, reopened.Notes);
+        Assert.Equal(nest.SalvageRate, reopened.SalvageRate);
+        var stock = Assert.Single(NestStockBuilder.FromTemplate(new Plate(48, 96), reopened.PlateOptions));
+        Assert.Equal(cost == 0 ? (double?)null : cost, stock.Cost);
+    }
+}

OpenNest.Mcp/NestSession.cs

@@ -17,6 +17,9 @@ namespace OpenNest.Mcp
 
         public Plate GetPlate(int index)
         {
+            if (index < 0)
+                return null;
+
             if (Nest != null && index < Nest.Plates.Count)
                 return Nest.Plates[index];
 
@@ -27,6 +30,38 @@ namespace OpenNest.Mcp
             return null;
         }
 
+        /// <summary>Remove only a genuinely unused sheet; loaded sheets precede appended sheets.</summary>
+        public bool TryDeleteEmptyPlate(int index, out string reason)
+        {
+            var plate = GetPlate(index);
+            if (plate == null)
+            {
+                reason = $"plate {index} not found";
+                return false;
+            }
+
+            if (plate.Parts.Count != 0)
+            {
+                reason = $"plate {index} is occupied";
+                return false;
+            }
+
+            if (plate.CutOffs.Count != 0)
+            {
+                reason = $"plate {index} has cutoff definitions";
+                return false;
+            }
+
+            var loadedCount = Nest?.Plates.Count ?? 0;
+            if (index < loadedCount)
+                Nest.Plates.RemoveAt(index);
+            else
+                Plates.RemoveAt(index - loadedCount);
+
+            reason = null;
+            return true;
+        }
+
         public Drawing GetDrawing(string name)
         {
             if (Nest != null)

OpenNest.Mcp/SheetStockInput.cs

@@ -0,0 +1,12 @@
+namespace OpenNest.Mcp;
+
+/// <summary>Request-local physical inventory for one whole-job solve.</summary>
+public sealed class SheetStockInput
+{
+    /// <summary>Positive per-sheet cost in common units; omit on every row for area scoring.</summary>
+    public double? Cost { get; set; }
+
+    public double Width { get; set; }
+    public double Length { get; set; }
+    public int Quantity { get; set; }
+}

OpenNest.Mcp/Tools/InputTools.cs

@@ -69,8 +69,24 @@ namespace OpenNest.Mcp.Tools
             [Description("Name for the nest (optional)")] string name = null
         )
         {
-            var nest = new Nest();
+            var source = _session.Nest;
-            nest.Name = name ?? Path.GetFileNameWithoutExtension(path);
+            var nest = new Nest
+            {
+                Name = name ?? (string.IsNullOrWhiteSpace(source?.Name) ? Path.GetFileNameWithoutExtension(path) : source.Name),
+                Customer = source?.Customer ?? "",
+                Notes = source?.Notes ?? "",
+                AssistGas = source?.AssistGas ?? "",
+                Status = source?.Status ?? NestStatus.Quote,
+                MadeBy = source?.MadeBy ?? "",
+                Thickness = source?.Thickness ?? 0,
+                Material = source?.Material ?? new Material(),
+                Units = source?.Units ?? default,
+                DateCreated = source?.DateCreated ?? default,
+                DateLastModified = source?.DateLastModified ?? default,
+                PlateDefaults = source?.PlateDefaults ?? new Nest.PlateSettings(),
+                PlateOptions = source?.PlateOptions ?? new(),
+                SalvageRate = source?.SalvageRate ?? 0.5,
+            };
 
             foreach (var drawing in _session.AllDrawings())
                 nest.Drawings.Add(drawing);

OpenNest.Mcp/Tools/NestingTools.cs

@@ -10,6 +10,7 @@ using OpenNest.Engine.Fill;
 using OpenNest.Engine.Jobs;
 using OpenNest.Engine.Jobs.Placement;
 using OpenNest.Geometry;
+using OpenNest.IO;
 
 namespace OpenNest.Mcp.Tools
 {
@@ -257,10 +258,7 @@ namespace OpenNest.Mcp.Tools
             sb.AppendLine($"  Total parts: {countAfter}");
             sb.AppendLine($"  Utilization: {plate.Utilization():P1}");
 
-            // Breakdown by drawing
+            AppendMixSummary(sb, items, parts);
-            var groups = plate.Parts.GroupBy(p => p.BaseDrawing.Name);
-            foreach (var group in groups)
-                sb.AppendLine($"  {group.Key}: {group.Count()}");
 
             return sb.ToString();
         }
@@ -333,11 +331,235 @@ namespace OpenNest.Mcp.Tools
             sb.AppendLine($"  Parts placed: {totalPlaced}");
             sb.AppendLine($"  Total parts: {plate.Parts.Count}");
             sb.AppendLine($"  Utilization: {plate.Utilization():P1}");
-            foreach (var group in plate.Parts.GroupBy(p => p.BaseDrawing.Name))
+            AppendMixSummary(sb, parsed.items, proposed == null ? Enumerable.Empty<Part>() : proposed.Parts);
-                sb.AppendLine($"  {group.Key}: {group.Count()}");
             return sb.ToString();
         }
 
+        [McpServerTool(Name = "autonest_job")]
+        [Description("Complete requested drawing quantities across physical sheets. The selected empty plate supplies common settings; optional sheets offer finite sizes and quantities. An incomplete or invalid proposal changes nothing.")]
+        public string AutoNestJob(
+            [Description("Index of an empty plate to use as the stock template")] int plateIndex,
+            [Description("Comma-separated drawing names")] string drawingNames,
+            [Description("Comma-separated total requested quantities for the entire session")] string quantities,
+            [Description(JobEngines)] string engine = null,
+            [Description("Use only already-created empty plates with matching dimensions and spacing; do not add sheets")] bool no_new_plates = false,
+            CancellationToken cancellationToken = default,
+            [Description("Optional finite physical sheet stock: width, length, available quantity and optional positive per-sheet cost in common units. Specify costs for every row or omit all. Incompatible with no_new_plates.")] SheetStockInput[] sheets = null
+        )
+        {
+            var template = _session.GetPlate(plateIndex);
+            if (template == null)
+                return $"Error: plate {plateIndex} not found";
+            if (template.Parts.Count != 0 || template.CutOffs.Count != 0)
+                return "Error: stock template must be empty and have no cutoff definitions. Nothing committed.";
+            if (sheets != null && no_new_plates)
+                return "Error: sheets cannot be combined with no_new_plates. Nothing committed.";
+            var offeredStock = BuildSheetStock(template, sheets);
+            if (offeredStock.error != null)
+                return offeredStock.error;
+            if (string.IsNullOrWhiteSpace(drawingNames) || string.IsNullOrWhiteSpace(quantities))
+                return "Error: drawingNames and quantities are required";
+            var parsed = ParseItems(drawingNames, quantities);
+            if (parsed.error != null)
+                return parsed.error;
+            if (parsed.items.Any(item => item.Quantity <= 0))
+                return "Error: whole-job quantities must be positive";
+
+            var existing = _session.AllPlates();
+            if (existing.Any(p => p.Parts.Count > 0 && p.Quantity <= 0))
+                return "Error: an occupied plate has a nonpositive quantity. Nothing committed.";
+            var remaining = new List<NestItem>(parsed.items.Count);
+            var counts = new Dictionary<Drawing, long>(ReferenceEqualityComparer.Instance);
+            foreach (var item in parsed.items)
+            {
+                var nested = existing.Sum(p => (long)p.Parts.Count(part => ReferenceEquals(part.BaseDrawing, item.Drawing)) * p.Quantity);
+                if (nested > item.Quantity)
+                    return $"Error: drawing '{item.Drawing.Name}' already exceeds requested quantity ({nested} > {item.Quantity}). Nothing committed.";
+                counts[item.Drawing] = nested;
+                if (nested < item.Quantity)
+                    remaining.Add(new NestItem
+                    {
+                        Drawing = item.Drawing,
+                        Quantity = (int)(item.Quantity - nested),
+                        Priority = item.Priority,
+                        StepAngle = item.StepAngle,
+                        RotationStart = item.RotationStart,
+                        RotationEnd = item.RotationEnd,
+                    });
+            }
+            if (remaining.Count == 0)
+                return "Job already complete: all requested quantities are present. Nothing committed.";
+
+            var available = new List<Plate> { template };
+            available.AddRange(existing.Where(p => !ReferenceEquals(p, template)
+                && p.Parts.Count == 0 && p.CutOffs.Count == 0 && SameStock(p, template)));
+            var demand = remaining.Sum(item => (long)item.Quantity);
+            if (demand > int.MaxValue)
+                return "Error: total remaining demand exceeds the supported sheet limit. Nothing committed.";
+            var limit = no_new_plates ? System.Math.Min(available.Count, (int)demand)
+                : sheets != null ? (int)System.Math.Min(offeredStock.total, demand) : (int)demand;
+            var engineName = string.IsNullOrWhiteSpace(engine) ? _session.DefaultEngineName : engine.Trim();
+            if (NestingEngineRegistry.ResolveName(engineName) == null)
+                return $"Error: unknown whole-job engine '{engineName}'. Nothing committed. Available: {string.Join(", ", NestingEngineRegistry.AvailableEngines.Select(e => e.Name))}";
+            NestPipelineResult result;
+            try
+            {
+                result = NestPipeline.Run(new NestPipelineRequest(engineName, remaining,
+                    sheets == null ? NestStockBuilder.FromTemplate(template, null, no_new_plates ? available.Count : null) : offeredStock.stock,
+                    new NestJobOptions(maxPlates: limit)), token: cancellationToken);
+            }
+            catch (NotSupportedException ex)
+            {
+                return $"Error: whole-job request unsupported: {ex.Message}. Nothing committed.";
+            }
+            cancellationToken.ThrowIfCancellationRequested();
+            if (!result.CanKeep || !result.IsValid)
+                return "Error: invalid whole-job proposal. Nothing committed. " + string.Join("; ", result.Violations);
+
+            var placed = new Dictionary<Drawing, long>(ReferenceEqualityComparer.Instance);
+            foreach (var sheet in result.Plates)
+                foreach (var part in sheet.Parts)
+                    placed[part.BaseDrawing] = placed.GetValueOrDefault(part.BaseDrawing) + 1;
+            if (remaining.Any(item => placed.GetValueOrDefault(item.Drawing) != item.Quantity))
+            {
+                var summary = string.Join(", ", remaining.Select(item =>
+                    $"{item.Drawing.Name}: {placed.GetValueOrDefault(item.Drawing)}/{item.Quantity} newly placed"));
+                return $"Error: incomplete whole-job proposal ({result.StopReason}); {summary}. Nothing committed. A solver's no-placement result does not prove geometric impossibility.";
+            }
+            if (result.Plates.Count > limit)
+                return "Error: proposal exceeds the allowed sheet count. Nothing committed.";
+
+            var costSummary = NestCostSummary.FromAccepted(result);
+
+            // Build the entire target map before attaching a single part. Indexes in a mixed
+            // stock proposal are solver ordinals, not indexes into the session's empty plates.
+            var usedTargets = new HashSet<Plate>(ReferenceEqualityComparer.Instance);
+            var targets = new List<(Plate plate, bool created, string stockId)>();
+            foreach (var proposed in result.Plates)
+            {
+                var target = new[] { template }.Concat(existing.Where(p => !ReferenceEquals(p, template)))
+                    .FirstOrDefault(p => !usedTargets.Contains(p)
+                        && p.Parts.Count == 0 && p.CutOffs.Count == 0
+                        && SameStock(p, template, proposed.Stock.Size));
+                var created = target == null;
+                target ??= new Plate(proposed.Stock.Size)
+                {
+                    GrainAngle = template.GrainAngle,
+                    CuttingParameters = template.CuttingParameters,
+                };
+                usedTargets.Add(target);
+                targets.Add((target, created, proposed.Stock.Id));
+            }
+            cancellationToken.ThrowIfCancellationRequested();
+            for (var i = 0; i < result.Plates.Count; i++)
+            {
+                var proposed = result.Plates[i];
+                var (target, created, _) = targets[i];
+                target.Size = proposed.Stock.Size;
+                target.PartSpacing = proposed.Stock.PartSpacing;
+                target.EdgeSpacing = proposed.Stock.EdgeSpacing;
+                target.Quadrant = proposed.Stock.Quadrant;
+                target.Quantity = 1;
+                if (created)
+                    _session.Plates.Add(target);
+                target.Parts.AddRange(proposed.Parts);
+            }
+            foreach (var item in parsed.items)
+                item.Drawing.Quantity.Required = item.Quantity;
+            if (sheets != null)
+            {
+                _session.Nest ??= new Nest();
+                _session.Nest.PlateOptions = offeredStock.stock.Select(s => new PlateOption
+                { Width = s.Size.Width, Length = s.Size.Length, Cost = s.Cost ?? 0 }).ToList();
+            }
+            var lines = new StringBuilder();
+            lines.AppendLine($"Cost basis={costSummary.Basis}, gross total={costSummary.GrossTotal}, estimated salvage credit={costSummary.SalvageCredit}, net score={costSummary.NetScore}");
+            foreach (var usage in costSummary.Stock)
+                lines.AppendLine($"  {usage.StockId}: used={usage.Used}, supplied cost={usage.Cost?.ToString() ?? "unspecified"}, gross subtotal={usage.GrossSubtotal}");
+            lines.AppendLine($"Whole job complete: {result.Plates.Count} sheet(s) placed, {targets.Count(t => t.created)} new sheet(s) created.");
+            if (sheets != null)
+            {
+                foreach (var stock in offeredStock.stock)
+                {
+                    var used = targets.Count(t => t.stockId == stock.Id);
+                    lines.AppendLine($"  {stock.Id} ({stock.Size.Width}x{stock.Size.Length}): used={used}, remaining={stock.Quantity - used}, reused={targets.Count(t => !t.created && t.stockId == stock.Id)}, created={targets.Count(t => t.created && t.stockId == stock.Id)}");
+                }
+                foreach (var (target, _, stockId) in targets)
+                    lines.AppendLine($"  plate {_session.AllPlates().FindIndex(p => ReferenceEquals(p, target))} -> {stockId}");
+            }
+            foreach (var item in parsed.items)
+                lines.AppendLine($"  {item.Drawing.Name}: requested={item.Quantity}, already={counts[item.Drawing]}, newly placed={placed.GetValueOrDefault(item.Drawing)}, remaining=0");
+            return lines.ToString();
+        }
+
+        private static (List<NestPlateStock> stock, long total, string error) BuildSheetStock(Plate template, SheetStockInput[] sheets)
+        {
+            if (sheets == null)
+                return (null, 0, null);
+            if (sheets.Length == 0)
+                return (null, 0, "Error: sheets must contain at least one stock size. Nothing committed.");
+            var stock = new List<NestPlateStock>(sheets.Length);
+            var priced = sheets.Any(s => s?.Cost != null);
+            long total = 0;
+            for (var i = 0; i < sheets.Length; i++)
+            {
+                var row = sheets[i];
+                if (row == null || !double.IsFinite(row.Width) || !double.IsFinite(row.Length)
+                    || !double.IsFinite(row.Width * row.Length)
+                    || row.Width <= 0 || row.Length <= 0 || row.Quantity <= 0
+                    || row.Length <= template.EdgeSpacing.Left + template.EdgeSpacing.Right
+                    || row.Width <= template.EdgeSpacing.Top + template.EdgeSpacing.Bottom)
+                    return (null, 0, $"Error: sheets[{i}] requires finite positive usable dimensions and a positive physical quantity. Nothing committed.");
+                if (row.Cost is double cost && (!double.IsFinite(cost) || cost <= 0)
+                    || priced && row.Cost == null)
+                    return (null, 0, $"Error: sheets[{i}] requires a finite positive cost; specify costs on every row or omit all. Nothing committed.");
+                var duplicate = stock.FindIndex(s => s.Size.Width == row.Width && s.Size.Length == row.Length);
+                if (duplicate >= 0)
+                    return (null, 0, $"Error: sheets[{i}] duplicates sheets[{duplicate}] size. Nothing committed.");
+                total += row.Quantity;
+                if (total > int.MaxValue)
+                    return (null, 0, "Error: total sheet inventory exceeds the supported sheet limit. Nothing committed.");
+                stock.Add(new NestPlateStock($"stock-{i}", new Size(row.Width, row.Length), row.Quantity,
+                    template.PartSpacing, template.EdgeSpacing, template.Quadrant, row.Cost));
+            }
+            return (stock, total, null);
+        }
+
+        private static bool SameStock(Plate a, Plate b) => SameStock(a, b, b.Size);
+
+        private static bool SameStock(Plate a, Plate b, Size size) =>
+            a.Size.Width == size.Width && a.Size.Length == size.Length
+            && a.PartSpacing == b.PartSpacing && a.EdgeSpacing.Equals(b.EdgeSpacing)
+            && a.Quadrant == b.Quadrant && a.GrainAngle == b.GrainAngle
+            && (a.CuttingParameters == null && b.CuttingParameters == null
+                || a.CuttingParameters != null && b.CuttingParameters != null
+                && string.Equals(CuttingParametersSerializer.Serialize(a.CuttingParameters),
+                    CuttingParametersSerializer.Serialize(b.CuttingParameters), StringComparison.Ordinal));
+
+        private static void AppendMixSummary(StringBuilder sb, IReadOnlyList<NestItem> items, IEnumerable<Part> newlyPlaced)
+        {
+            var counts = new Dictionary<Drawing, int>(ReferenceEqualityComparer.Instance);
+            foreach (var part in newlyPlaced)
+                counts[part.BaseDrawing] = counts.TryGetValue(part.BaseDrawing, out var n) ? n + 1 : 1;
+
+            var placed = new int[items.Count];
+            sb.AppendLine("  Requested mix (new placements only):");
+            for (var i = 0; i < items.Count; i++)
+            {
+                var item = items[i];
+                placed[i] = counts.GetValueOrDefault(item.Drawing);
+                var remaining = item.Quantity - placed[i];
+                sb.AppendLine($"    [{i}] {item.Drawing.Name}: requested={item.Quantity}, placed={placed[i]}, remaining={remaining}");
+            }
+
+            if (placed.All(count => count == 0))
+                sb.AppendLine("  Mix: zero progress for all requested drawings.");
+            else if (items.Where((item, i) => item.Quantity > placed[i]).Any())
+                sb.AppendLine("  Warning: remaining demand in this call; place the outstanding quantities on another sheet before treating the job as complete.");
+            else
+                sb.AppendLine("  Mix: requested quantities placed in this call.");
+        }
+
         /// <summary>
         /// Resolves the requested fill strategy; an omitted name means Fill. Returns null when the
         /// name is not a single-plate placement strategy.
@@ -376,6 +598,8 @@ namespace OpenNest.Mcp.Tools
             {
                 if (!int.TryParse(qtyStrings[i], out qtys[i]))
                     return (null, $"Error: '{qtyStrings[i]}' is not a valid quantity");
+                if (qtys[i] < 0)
+                    return (null, $"Error: negative quantity '{qtys[i]}' is not supported");
             }
 
             if (names.Length != qtys.Length)
@@ -385,14 +609,28 @@ namespace OpenNest.Mcp.Tools
                 );
 
             var items = new List<NestItem>();
+            var seen = new HashSet<Drawing>(ReferenceEqualityComparer.Instance);
 
             for (var i = 0; i < names.Length; i++)
             {
-                var drawing = _session.GetDrawing(names[i]);
+                var matches = _session.AllDrawings().Where(d => d.Name == names[i]).ToArray();
-                if (drawing == null)
+                if (matches.Length == 0)
                     return (null, $"Error: drawing '{names[i]}' not found");
+                if (matches.Length > 1)
+                    return (null, $"Error: ambiguous drawing name '{names[i]}' matches multiple drawings");
+                var drawing = matches[0];
+                if (!seen.Add(drawing))
+                    return (null, $"Error: duplicate drawing '{names[i]}' in request");
 
-                items.Add(new NestItem { Drawing = drawing, Quantity = qtys[i] });
+                items.Add(new NestItem
+                {
+                    Drawing = drawing,
+                    Quantity = qtys[i],
+                    Priority = drawing.Priority,
+                    StepAngle = drawing.Constraints?.StepAngle ?? 0,
+                    RotationStart = drawing.Constraints?.StartAngle ?? 0,
+                    RotationEnd = drawing.Constraints?.EndAngle ?? 0,
+                });
             }
 
             return (items, null);

OpenNest.Mcp/Tools/SetupTools.cs

@@ -58,6 +58,22 @@ namespace OpenNest.Mcp.Tools
             return sb.ToString();
         }
 
+        [McpServerTool(Name = "delete_plate")]
+        [Description("Delete an empty plate without parts or cutoff definitions. Later plate indices shift down by one.")]
+        public string DeletePlate([Description("Index of the empty plate to delete")] int plateIndex)
+        {
+            var oldCount = _session.AllPlates().Count;
+            if (!_session.TryDeleteEmptyPlate(plateIndex, out var reason))
+                return $"Error: {reason}; no plates changed";
+
+            var sb = new StringBuilder();
+            sb.AppendLine($"Deleted plate {plateIndex}. Plates: {oldCount} -> {oldCount - 1}.");
+            for (var oldIndex = plateIndex + 1; oldIndex < oldCount; oldIndex++)
+                sb.AppendLine($"  {oldIndex} -> {oldIndex - 1}");
+            sb.AppendLine("Use get_plate_info with the new indices before further operations.");
+            return sb.ToString();
+        }
+
         [McpServerTool(Name = "clear_plate")]
         [Description("Remove all parts from a plate. Returns how many parts were removed.")]
         public string ClearPlate([Description("Index of the plate to clear")] int plateIndex)

OpenNest.Reporting/NestPdfWriter.cs

@@ -25,7 +25,6 @@ public static class NestPdfWriter
     private const double PortraitWidth = 540;
     private const double LandscapeWidth = 720;
     private const double OverviewHeight = 320;
-    private const double DetailHeight = 400;
 
     private static readonly XColor Fill = XColor.FromArgb(222, 222, 222);
     private static readonly CultureInfo Invariant = CultureInfo.InvariantCulture;
@@ -54,7 +53,7 @@ public static class NestPdfWriter
 
         // Plan every diagram before layout; nothing below touches the destination until Save.
         var plans = snapshot.Plates.Select(plate =>
-            NestReportDiagram.Plan(plate, LandscapeWidth, OverviewHeight, DetailHeight)).ToList();
+            NestReportDiagram.Plan(plate, LandscapeWidth, OverviewHeight)).ToList();
 
         var document = new Document();
         document.Info.Title = snapshot.Name;
@@ -131,7 +130,7 @@ public static class NestPdfWriter
         else
         {
             var plates = AddTable(section, 60, 200, 80, 100, 100);
-            AddHeader(plates, "Plate", "Stock size", "Copies", "Parts/sheet", "Utilization");
+            AddHeader(plates, "Plate", "Stock size", "Quantity", "Parts per plate", "Utilization");
             foreach (var plate in snapshot.Plates)
                 AddRow(plates, $"Plate {plate.Number}", false, plate.Number.ToString(Invariant), SheetSize(snapshot, plate),
                     plate.Copies.ToString(Invariant), plate.Parts.Length.ToString(Invariant), Percent(plate.Utilization));
@@ -158,7 +157,7 @@ public static class NestPdfWriter
     }
 
     private static void AddPlate(Document document, NestReportSnapshot snapshot, ReportPlate plate,
-        PlateDiagramPlan plan, List<(Table, Action<XGraphics, XRect>)> areas)
+        DiagramView plan, List<(Table, Action<XGraphics, XRect>)> areas)
     {
         var heading = $"Plate {plate.Number} of {snapshot.Plates.Length}";
         var header = new List<string> { $"Nest report: {snapshot.Name}", heading, SheetSize(snapshot, plate) };
@@ -172,30 +171,23 @@ public static class NestPdfWriter
         title.Format.Font.Size = 13;
         title.Format.Font.Bold = true;
 
-        var info = AddTable(section, 80, 280, 90, 270);
+        var info = AddTable(section, 100, 260, 90, 270);
         info.Borders.Visible = false;
         AddInfoRow(info, "Nest:", snapshot.Name, "Sheet size:", SheetSize(snapshot, plate));
-        AddInfoRow(info, "Material:", Material(snapshot), "Copies:", plate.Copies.ToString(Invariant));
+        AddInfoRow(info, "Material:", Material(snapshot), "Quantity:", plate.Copies.ToString(Invariant));
         AddInfoRow(info, "Thickness:", Thickness(snapshot), "Part spacing:",
             $"{Number(plate.PartSpacing)} {snapshot.Units}");
-        AddInfoRow(info, "Parts/sheet:", plate.Parts.Length.ToString(Invariant), "Utilization:",
+        AddInfoRow(info, "Parts per plate:", plate.Parts.Length.ToString(Invariant), "Utilization:",
             Percent(plate.Utilization) + " (net part area / full sheet)");
 
-        var overview = AddReservedArea(section, null, plan.Overview.Size.Height);
+        var overview = AddReservedArea(section, plan.Size.Height);
-        areas.Add((overview, (gfx, _) => DrawView(gfx, plate, plan.Overview)));
+        areas.Add((overview, (gfx, _) => DrawView(gfx, plate, plan)));
 
         var legend = section.AddParagraph("Filled outlines are closed parts; open material paths such as tab gaps are shown without fill. Dashed lines are scrap cutoffs.");
         legend.Format.Font.Size = 7.5;
         legend.Format.SpaceBefore = Unit.FromPoint(4);
-        if (plan.Overview.Grid is { } grid)
+        var labelsNote = section.AddParagraph("Part IDs are shown where space permits. A dotted outline groups like parts under one ID.");
-        {
+        labelsNote.Format.Font.Size = 7.5;
-            var names = string.Join(", ", plan.Details.Select(detail => detail.Cell));
-            var fallback = section.AddParagraph();
-            fallback.Format.Font.Size = 7.5;
-            AddLines(fallback, ReportText.Wrap(
-                $"Some part IDs are too small to label at this scale. Grid rows are lettered from the top and columns numbered from the left; cells outlined dash-dot have detail views on the following pages: {names}.",
-                new XFont(ReportFonts.Family, 7.5), LandscapeWidth));
-        }
         var approval = section.AddParagraph("This report is not a geometry or CNC approval.");
         approval.Format.Font.Size = 7.5;
         approval.Format.SpaceAfter = Unit.FromPoint(4);
@@ -204,36 +196,23 @@ public static class NestPdfWriter
         var perSheet = plate.Parts.GroupBy(part => part.ReportId, StringComparer.Ordinal)
             .ToDictionary(group => group.Key, group => (long)group.Count(), StringComparer.Ordinal);
         var parts = AddTable(section, 60, 400, 110, 150);
-        AddHeader(parts, "ID", "Drawing", "Qty/sheet", $"Total ({plate.Copies} copies)");
+        AddHeader(parts, "ID", "Drawing", "Parts per plate", $"Total ({plate.Copies} plates)");
         foreach (var drawing in snapshot.Drawings.Where(drawing => perSheet.ContainsKey(drawing.Id)))
         {
             var count = perSheet[drawing.Id];
             AddRow(parts, $"Plate {plate.Number}, drawing {drawing.Id}", false, drawing.Id, names2[drawing.Id],
                 count.ToString(Invariant), checked(count * plate.Copies).ToString(Invariant));
         }
-
-        foreach (var detail in plan.Details)
-        {
-            var bounds = detail.CellBounds!;
-            var caption = $"Plate {plate.Number} detail {detail.Cell}: X {Number(bounds.Left)} to {Number(bounds.Right)}, Y {Number(bounds.Bottom)} to {Number(bounds.Top)} {snapshot.Units}. Parts centered in the dash-dot cell are labeled.";
-            var table = AddReservedArea(section, caption, detail.Size.Height);
-            areas.Add((table, (gfx, _) => DrawView(gfx, plate, detail)));
-        }
     }
 
     /// <summary>A fixed-height, never-split table row reserves a vector drawing area in MigraDoc's flow.</summary>
-    private static Table AddReservedArea(Section section, string? caption, double height)
+    private static Table AddReservedArea(Section section, double height)
     {
         var table = AddTable(section, LandscapeWidth);
         table.Borders.Visible = false;
         table.LeftPadding = table.RightPadding = Unit.Zero;
         table.TopPadding = table.BottomPadding = Unit.Zero;
         table.Format.SpaceBefore = Unit.FromPoint(4);
-        if (caption != null)
-        {
-            var row = AddRow(table, "Detail caption", true, caption);
-            row.KeepWith = 1;
-        }
         var reserved = table.AddRow();
         reserved.HeightRule = RowHeightRule.Exactly;
         reserved.Height = Unit.FromPoint(height);
@@ -276,14 +255,6 @@ public static class NestPdfWriter
     private static void DrawView(XGraphics gfx, ReportPlate plate, DiagramView view)
     {
         var fit = view.Fit;
-        // Detail views clip exactly at their frame line so cropped neighbours stop there.
-        var frame = new XRect(0.5, 0.5, view.Size.Width - 1, view.Size.Height - 1);
-        var state = gfx.Save();
-        if (view.CellBounds != null)
-            gfx.IntersectClip(frame);
-        // The map grid lies beneath the sheet and parts so it never hides an outline.
-        if (view.Grid is { } grid)
-            DrawGrid(gfx, grid, fit);
         gfx.DrawRectangle(new XPen(XColors.Black, 1), fit.Rect(plate.Bounds));
         var outline = new XPen(XColors.Black, 0.6);
         foreach (var part in plate.Parts)
@@ -293,54 +264,15 @@ public static class NestPdfWriter
         var cutoff = new XPen(XColors.Black, 0.75) { DashPattern = [9, 3] };
         foreach (var geometry in plate.Cutoffs)
             StrokeContours(gfx, geometry, fit, cutoff);
-        // Long dash-dot, so detail cells are never confused with dashed scrap cutoffs.
+        var groupPen = new XPen(XColors.Black, 0.6) { DashPattern = [1, 3] };
-        var detail = new XPen(XColors.Black, 1.6) { DashPattern = [9, 3, 1, 3] };
+        foreach (var group in view.Groups)
-        if (view.Grid is { } overviewGrid)
+            gfx.DrawRectangle(groupPen, group.Boundary);
-        {
-            foreach (var (row, column) in overviewGrid.DetailCells)
-                gfx.DrawRectangle(detail, fit.Rect(overviewGrid.Cell(row, column)));
-        }
-        if (view.CellBounds is { } cell)
-            gfx.DrawRectangle(detail, fit.Rect(cell));
         var font = NestReportDiagram.LabelFont();
-        foreach (var label in view.Labels)
+        foreach (var label in view.Labels.Concat(view.Groups.Select(group => group.Label)))
         {
             gfx.DrawRectangle(XBrushes.White, label.Box);
             gfx.DrawString(label.Id, font, XBrushes.Black, label.Box, XStringFormats.Center);
         }
-        gfx.Restore(state);
-        // Frame the viewport so cropped neighbouring parts read as intentional.
-        if (view.CellBounds != null)
-            gfx.DrawRectangle(new XPen(XColors.Gray, 0.75), frame);
-    }
-
-    private static void DrawGrid(XGraphics gfx, DiagramGrid grid, Fit fit)
-    {
-        var line = new XPen(XColors.Gray, 0.3) { DashPattern = [3, 6] };
-        var area = fit.Rect(grid.Union);
-        for (var column = 0; column <= grid.Columns; column++)
-        {
-            var x = area.X + column * grid.CellLength * fit.Scale;
-            gfx.DrawLine(line, x, area.Y, x, area.Y + grid.Rows * grid.CellWidth * fit.Scale);
-        }
-        for (var row = 0; row <= grid.Rows; row++)
-        {
-            var y = area.Y + row * grid.CellWidth * fit.Scale;
-            gfx.DrawLine(line, area.X, y, area.X + grid.Columns * grid.CellLength * fit.Scale, y);
-        }
-        var font = NestReportDiagram.LabelFont();
-        for (var column = 0; column < grid.Columns; column++)
-        {
-            var x = area.X + (column + 0.5) * grid.CellLength * fit.Scale;
-            gfx.DrawString((column + 1).ToString(Invariant), font, XBrushes.Black,
-                new XRect(x - 20, area.Y - 11, 40, 10), XStringFormats.BottomCenter);
-        }
-        for (var row = 0; row < grid.Rows; row++)
-        {
-            var y = area.Y + (row + 0.5) * grid.CellWidth * fit.Scale;
-            gfx.DrawString(ReportText.RowName(row), font, XBrushes.Black,
-                new XRect(area.X - 16, y - 5, 14, 10), XStringFormats.CenterRight);
-        }
     }
 
     private static string Thumbnail(ReportGeometry geometry)
@@ -532,7 +464,7 @@ public static class NestPdfWriter
         snapshot.Thickness > 0 ? $"{Number(snapshot.Thickness)} {snapshot.Units}" : "Not specified";
 
     private static string SheetSize(NestReportSnapshot snapshot, ReportPlate plate) =>
-        $"{Number(plate.Bounds.Length)} x {Number(plate.Bounds.Width)} {snapshot.Units}";
+        $"{Number(plate.Bounds.Width)} x {Number(plate.Bounds.Length)} {snapshot.Units}";
 
     private static string Number(double value) => value.ToString("0.####", Invariant);
 

OpenNest.Reporting/NestReportBuilder.cs

@@ -21,13 +21,19 @@ public static class NestReportBuilder
         {
             if (byReference.TryGetValue(drawing, out var existing))
                 return existing;
-            var item = new DrawingCount(drawing, "R" + (ordered.Count + 1).ToString("D3", CultureInfo.InvariantCulture));
+            var item = new DrawingCount(drawing, (ordered.Count + 1).ToString(CultureInfo.InvariantCulture));
             byReference.Add(drawing, item);
             ordered.Add(item);
             return item;
         }
 
-        for (var index = 0; index < nest.Plates.Count; index++)
+        // The editor can leave unused stock at the end of a job. Exclude those placeholders
+        // from report pages and totals without changing plate numbers or the live nest.
+        var plateCount = nest.Plates.Count;
+        while (plateCount > 0 && nest.Plates[plateCount - 1]?.Parts.Count == 0)
+            plateCount--;
+
+        for (var index = 0; index < plateCount; index++)
         {
             var number = index + 1;
             var plate = nest.Plates[index];

OpenNest.Reporting/NestReportDiagram.cs

@@ -6,43 +6,20 @@ namespace OpenNest.Reporting;
 /// <summary>A part ID label in canvas-local page coordinates (Y down).</summary>
 internal sealed record DiagramLabel(int Part, string Id, XRect Box);
 
-/// <summary>Map grid over the overview; rows are lettered from the top, columns numbered from the left.</summary>
+/// <summary>A dotted group boundary and its shared ID, in canvas coordinates.</summary>
-internal sealed record DiagramGrid(ReportBounds Union, double CellLength, double CellWidth, int Columns, int Rows,
+internal sealed record DiagramGroup(IReadOnlyList<int> Parts, XRect Boundary, DiagramLabel Label);
-    IReadOnlyList<(int Row, int Column)> DetailCells)
-{
-    public string Name(int row, int column) => ReportText.RowName(row) + (column + 1).ToString(System.Globalization.CultureInfo.InvariantCulture);
 
-    public ReportBounds Cell(int row, int column)
-    {
-        var left = Union.Left + column * CellLength;
-        var top = Union.Top - row * CellWidth;
-        return new ReportBounds(left, top - CellWidth, left + CellLength, top);
-    }
-}
-
-/// <summary>One drawn view of a plate: the fitted overview or a zoomed grid-cell detail.</summary>
 internal sealed record DiagramView(XSize Size, Fit Fit, IReadOnlyList<DiagramLabel> Labels,
-    DiagramGrid? Grid, string? Cell, ReportBounds? CellBounds);
+    IReadOnlyList<DiagramGroup> Groups);
 
-internal sealed record PlateDiagramPlan(DiagramView Overview, IReadOnlyList<DiagramView> Details);
+/// <summary>Plans best-effort labels on a single plate view; small repeated parts may share a label.</summary>
-
-/// <summary>
-/// Plans labels before any PDF output. IDs are never shrunk below <see cref="LabelFontSize"/> or
-/// dropped: a label that cannot sit legibly inside its part's material at overview scale is placed
-/// in a zoomed map-grid detail view instead, or the report fails with the part identified.
-/// </summary>
 internal static class NestReportDiagram
 {
     internal const double LabelFontSize = 7;
-    internal const int MaxDetailViews = 24;
     private const double LabelPadding = 1;
     // Minimum white space between a label and any edge, hole, cutoff or other label.
     private const double Clearance = 1.5;
     private const double Inset = 5;
-    private const double GutterLeft = 16;
-    private const double GutterTop = 12;
-    private const double DetailMargin = 0.08;
-    private static readonly double[] Zooms = [1, 2, 4];
 
     internal static XFont LabelFont()
     {
@@ -58,100 +35,100 @@ internal static class NestReportDiagram
     internal static double PolePrecision(ReportBounds bounds) =>
         System.Math.Max(System.Math.Max(bounds.Length, bounds.Width) * 0.005, 1e-9);
 
-    internal static PlateDiagramPlan Plan(ReportPlate plate, double width, double overviewHeight, double detailHeight)
+    internal static DiagramView Plan(ReportPlate plate, double width, double height)
     {
         var shapes = plate.Parts.Select(part => new Shape(part.Geometry)).ToList();
         var obstacles = shapes.Concat(plate.Cutoffs.Select(cutoff => new Shape(cutoff))).ToList();
         var union = Union(plate, obstacles);
         var font = LabelFont();
         var all = Enumerable.Range(0, plate.Parts.Length).ToList();
-        var canvas = new XSize(width, overviewHeight);
+        var canvas = new XSize(width, height);
-        var overviewView = new XRect(0, 0, width, overviewHeight);
+        var view = new XRect(0, 0, width, height);
+        var fit = Fit.Create(union, new XRect(Inset, Inset, width - 2 * Inset, height - 2 * Inset));
+        var labels = PlaceLabels(plate, shapes, obstacles, all, fit, view, font, out var failed);
+        var groups = PlaceGroups(plate, failed, labels, fit, view, font);
+        return new DiagramView(canvas, fit, labels, groups);
+    }
 
-        var fit = Fit.Create(union, new XRect(Inset, Inset, width - 2 * Inset, overviewHeight - 2 * Inset));
+    private static List<DiagramGroup> PlaceGroups(ReportPlate plate, List<int> failed,
-        var labels = PlaceLabels(plate, shapes, obstacles, all, fit, overviewView, font, out var failed);
+        List<DiagramLabel> labels, Fit fit, XRect view, XFont font)
-        if (failed.Count == 0)
-            return new PlateDiagramPlan(new DiagramView(canvas, fit, labels, null, null, null), []);
-
-        // Reserve map-grid gutters, then re-place what still fits at overview scale.
-        fit = Fit.Create(union, new XRect(GutterLeft, GutterTop, width - GutterLeft - Inset, overviewHeight - GutterTop - Inset));
-        labels = PlaceLabels(plate, shapes, obstacles, all, fit, overviewView, font, out failed);
-        var failedSet = failed.ToHashSet();
-        var required = failed.Max(index => RequiredScale(plate, index, font));
-        var inner = new XRect(Inset, Inset, width - 2 * Inset, detailHeight - 2 * Inset);
-        var legibleGrid = false;
-        foreach (var zoom in Zooms)
     {
-            var scale = required * zoom;
+        var boxes = plate.Parts.Select(part => fit.Rect(part.Geometry.Bounds)).ToList();
-            // Cells evenly divide the sheet (no overrun); each is at most the size a detail view
+        var cutoffs = plate.Cutoffs.Select(cutoff => fit.Rect(cutoff.Bounds)).ToList();
-            // shows at the required scale, so the zoom only increases.
+        var groups = new List<DiagramGroup>();
-            var columns = System.Math.Max(1, (int)System.Math.Ceiling(union.Length * scale * (1 + 2 * DetailMargin) / inner.Width));
+        // A small screen-space gap also accommodates tightly packed parts with unset spacing.
-            var rows = System.Math.Max(1, (int)System.Math.Ceiling(union.Width * scale * (1 + 2 * DetailMargin) / inner.Height));
+        var gap = System.Math.Max(4, plate.PartSpacing * fit.Scale * 2);
-            var cellLength = union.Length / columns;
+        var remaining = failed.ToHashSet();
-            var cellWidth = union.Width / rows;
+        foreach (var seed in failed)
-            var grid = new DiagramGrid(union, cellLength, cellWidth, columns, rows, []);
+        {
-            // Every grid line and gutter name must stay readable on the overview.
+            if (!remaining.Remove(seed))
-            if (!GridIsLegible(grid, fit, font))
                 continue;
-            legibleGrid = true;
+            var id = plate.Parts[seed].ReportId;
-            (int Row, int Column) CellOf(int index) => CellIndex(plate, index, union, columns, rows);
+            var members = new List<int> { seed };
-
+            for (var cursor = 0; cursor < members.Count; cursor++)
-            var cells = failed.Select(CellOf).Distinct().OrderBy(cell => cell.Row).ThenBy(cell => cell.Column).ToList();
-            if (cells.Count > MaxDetailViews)
-                throw new NotSupportedException($"Plate {plate.Number}: legible part ID labels would need {cells.Count} detail views; this report supports at most {MaxDetailViews} per plate.");
-            grid = grid with { DetailCells = cells };
-            var details = new List<DiagramView>();
-            var unplaced = new List<int>();
-            foreach (var (row, column) in cells)
             {
-                var cell = grid.Cell(row, column);
+                var nearby = boxes[members[cursor]];
-                var marginX = cellLength * DetailMargin;
+                nearby.Inflate(gap, gap);
-                var marginY = cellWidth * DetailMargin;
+                foreach (var candidate in failed)
-                var view = new ReportBounds(cell.Left - marginX, cell.Bottom - marginY, cell.Right + marginX, cell.Top + marginY);
-                var detailFit = Fit.Create(view, inner);
-                // Parts missing from the overview claim label space first.
-                var members = all.Where(index => CellOf(index) == (row, column))
-                    .OrderBy(index => failedSet.Contains(index) ? 0 : 1).ToList();
-                var detailLabels = PlaceLabels(plate, shapes, obstacles, members, detailFit,
-                    new XRect(0, 0, width, detailHeight), font, out var missed);
-                unplaced.AddRange(missed.Where(failedSet.Contains));
-                details.Add(new DiagramView(new XSize(width, detailHeight), detailFit, detailLabels, null,
-                    grid.Name(row, column), cell));
-            }
-            if (unplaced.Count == 0)
-                return new PlateDiagramPlan(new DiagramView(canvas, fit, labels, grid, null, null), details);
-        }
-
-        var worst = failed.First();
-        if (!legibleGrid)
-            throw new NotSupportedException($"Plate {plate.Number}, part {worst + 1} ({plate.Parts[worst].ReportId}): the part is too small relative to the sheet for a legible detail-view grid; this is not supported by the report.");
-        throw new NotSupportedException($"Plate {plate.Number}, part {worst + 1} ({plate.Parts[worst].ReportId}): its ID label cannot be placed legibly inside the part's material, even in a zoomed detail view; this is not supported by the report.");
-    }
-
-    /// <summary>Grid cell holding a part's bounds center; rows count down from the top.</summary>
-    private static (int Row, int Column) CellIndex(ReportPlate plate, int index, ReportBounds union, int columns, int rows)
                 {
-        var bounds = plate.Parts[index].Geometry.Bounds;
+                    if (remaining.Contains(candidate) && plate.Parts[candidate].ReportId == id
-        var x = (bounds.Left + bounds.Right) / 2;
+                        && nearby.IntersectsWith(boxes[candidate]))
-        var y = (bounds.Bottom + bounds.Top) / 2;
-        return (System.Math.Clamp((int)((union.Top - y) / (union.Width / rows)), 0, rows - 1),
-            System.Math.Clamp((int)((x - union.Left) / (union.Length / columns)), 0, columns - 1));
-    }
-
-    /// <summary>Grid spacing on the overview must exceed the gutter names it carries.</summary>
-    internal static bool GridIsLegible(DiagramGrid grid, Fit fit, XFont font)
                     {
-        var column = ReportText.Size(grid.Columns.ToString(System.Globalization.CultureInfo.InvariantCulture), font);
+                        remaining.Remove(candidate);
-        var row = ReportText.Size(ReportText.RowName(grid.Rows - 1), font);
+                        members.Add(candidate);
-        return grid.CellLength * fit.Scale >= column.Width + 2 && grid.CellWidth * fit.Scale >= row.Height + 1
+                    }
-            && row.Width + 2 <= GutterLeft && column.Height + 2 <= GutterTop;
+                }
+            }
+            if (members.Count < 2)
+                continue;
+
+            var boundary = boxes[seed];
+            foreach (var member in members.Skip(1))
+                boundary.Union(boxes[member]);
+            boundary.Inflate(1, 1);
+            var memberSet = members.ToHashSet();
+            // A rectangular group must not imply that unrelated or ungrouped parts belong to it.
+            if (!view.Contains(boundary)
+                || boxes.Where((_, index) => !memberSet.Contains(index)).Any(box => box.IntersectsWith(boundary))
+                || cutoffs.Any(box => box.IntersectsWith(boundary))
+                || labels.Any(label => label.Box.IntersectsWith(boundary))
+                || groups.Any(group => group.Boundary.IntersectsWith(boundary) || group.Label.Box.IntersectsWith(boundary)))
+                continue;
+
+            var size = ReportText.Size(id, font);
+            var labelWidth = size.Width + 2 * LabelPadding;
+            var labelHeight = size.Height + 2 * LabelPadding;
+            var centerX = boundary.X + (boundary.Width - labelWidth) / 2;
+            var centerY = boundary.Y + (boundary.Height - labelHeight) / 2;
+            // Put the ID beside the dotted boundary, never over a small part or its hole.
+            var candidates = new[]
+            {
+                new XRect(centerX, boundary.Y - labelHeight - Clearance, labelWidth, labelHeight),
+                new XRect(centerX, boundary.Bottom + Clearance, labelWidth, labelHeight),
+                new XRect(boundary.Right + Clearance, centerY, labelWidth, labelHeight),
+                new XRect(boundary.X - labelWidth - Clearance, centerY, labelWidth, labelHeight),
+            };
+            foreach (var box in candidates)
+            {
+                var padded = box;
+                padded.Inflate(Clearance, Clearance);
+                if (!view.Contains(padded) || boxes.Any(other => other.IntersectsWith(padded))
+                    || cutoffs.Any(other => other.IntersectsWith(padded))
+                    || labels.Any(label => label.Box.IntersectsWith(padded))
+                    || groups.Any(group => group.Boundary.IntersectsWith(padded) || group.Label.Box.IntersectsWith(padded)))
+                    continue;
+                groups.Add(new DiagramGroup(members, boundary, new DiagramLabel(seed, id, box)));
+                break;
+            }
+        }
+        return groups;
     }
 
     /// <summary>
     /// Centers each ID on its part's pole of inaccessibility (<see cref="PolyLabel"/>, as PlateView
     /// does), so it sits deepest inside the material and clear of holes. A label box that would
-    /// touch an edge, hole, cutoff or another label is not moved elsewhere: the part fails here
+    /// touch an edge, hole, cutoff or another label is not moved elsewhere: the individual label is skipped here
-    /// and gets a zoomed detail view instead.
+    /// and may share a group label or remain unlabeled.
     /// </summary>
     private static List<DiagramLabel> PlaceLabels(ReportPlate plate, List<Shape> shapes, List<Shape> obstacles,
         List<int> targets, Fit fit, XRect view, XFont font, out List<int> failed)
@@ -178,20 +155,6 @@ internal static class NestReportDiagram
         return placed;
     }
 
-    /// <summary>Scale at which the label would fit the part's bounds, with room to avoid holes and strokes.</summary>
-    private static double RequiredScale(ReportPlate plate, int index, XFont font)
-    {
-        var bounds = plate.Parts[index].Geometry.Bounds;
-        if (!(bounds.Length > 0) || !(bounds.Width > 0))
-            throw new NotSupportedException($"Plate {plate.Number}, part {index + 1} ({plate.Parts[index].ReportId}): the part has no area to hold its ID label; this is not supported by the report.");
-        var size = ReportText.Size(plate.Parts[index].ReportId, font);
-        var scale = System.Math.Max((size.Width + 2 * (LabelPadding + Clearance)) / bounds.Length,
-            (size.Height + 2 * (LabelPadding + Clearance)) / bounds.Width) * 1.5;
-        if (!double.IsFinite(scale))
-            throw new NotSupportedException($"Plate {plate.Number}, part {index + 1} ({plate.Parts[index].ReportId}): the part is too small to hold a legible ID label.");
-        return scale;
-    }
-
     private static ReportBounds Union(ReportPlate plate, IEnumerable<Shape> shapes)
     {
         var left = plate.Bounds.Left;

OpenNest.Server.Tests/NestDatabaseConcurrencyTests.cs

@@ -24,7 +24,7 @@ public sealed class NestDatabaseConcurrencyTests
     public async Task Concurrency_EveryOperationWaitsForTheSameMonitor(string operation)
     {
         using var factory = new ServerFactory();
-        using var database = new NestDatabase(factory.DatabasePath);
+        using var database = new NestDatabase(factory.DatabasePath, pooling: false);
         var id = Guid.NewGuid();
         var record = new NestRecord { Name = "Monitor ownership fixture" };
         database.Insert(id, record, new byte[] { 1, 2, 3 });
@@ -75,7 +75,7 @@ public sealed class NestDatabaseConcurrencyTests
     public void Concurrency_AllSqlStepsIncludingReadbacks_OwnTheMonitor()
     {
         using var factory = new ServerFactory();
-        using var database = new NestDatabase(factory.DatabasePath);
+        using var database = new NestDatabase(factory.DatabasePath, pooling: false);
         var sync = typeof(NestDatabase).GetField("_sync", BindingFlags.Instance | BindingFlags.NonPublic)!
             .GetValue(database)!;
         var connection = (SqliteConnection)typeof(NestDatabase)
@@ -125,7 +125,7 @@ public sealed class NestDatabaseConcurrencyTests
     public async Task Concurrency_DatabaseReadersAndWriters_PreserveExactRecords()
     {
         using var factory = new ServerFactory();
-        using var database = new NestDatabase(factory.DatabasePath);
+        using var database = new NestDatabase(factory.DatabasePath, pooling: false);
         using var start = new Barrier(4);
         var workers = Enumerable.Range(0, 4).Select(lane => Task.Factory.StartNew(() =>
         {

OpenNest.Server.Tests/ServerFactory.cs

@@ -1,7 +1,6 @@
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.Mvc.Testing;
 using Microsoft.AspNetCore.TestHost;
-using Microsoft.Data.Sqlite;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.DependencyInjection.Extensions;
 
@@ -16,6 +15,7 @@ namespace OpenNest.Server.Tests;
 public sealed class ServerFactory : WebApplicationFactory<global::Program>
 {
     private bool _cleanedUp;
+    private NestDatabase? _database;
 
     public ServerFactory(string? databasePath = null)
     {
@@ -34,7 +34,8 @@ public sealed class ServerFactory : WebApplicationFactory<global::Program>
         builder.ConfigureTestServices(services =>
         {
             services.RemoveAll<NestDatabase>();
-            services.AddSingleton(_ => new NestDatabase(DatabasePath));
+            // Register an externally owned instance; this factory closes it before deleting its file.
+            services.AddSingleton(_database = new NestDatabase(DatabasePath, pooling: false));
         });
     }
 
@@ -45,8 +46,7 @@ public sealed class ServerFactory : WebApplicationFactory<global::Program>
             return;
 
         _cleanedUp = true;
-        // Pooled connections would keep the file open on Windows after the host disposed it.
+        _database?.Dispose();
-        SqliteConnection.ClearAllPools();
         if (Directory.Exists(DirectoryPath))
             Directory.Delete(DirectoryPath, recursive: true);
     }

OpenNest.Server/NestDatabase.cs

@@ -16,13 +16,18 @@ public sealed class NestDatabase : IDisposable
     private readonly object _sync = new();
     private readonly SqliteConnection _connection;
 
-    public NestDatabase(string databasePath)
+    public NestDatabase(string databasePath, bool pooling = true)
     {
         var directory = Path.GetDirectoryName(Path.GetFullPath(databasePath));
         if (!string.IsNullOrEmpty(directory))
             Directory.CreateDirectory(directory);
 
-        _connection = new SqliteConnection($"Data Source={databasePath}");
+        // Test databases are short-lived files: disabling pooling releases Windows file handles on dispose.
+        _connection = new SqliteConnection(new SqliteConnectionStringBuilder
+        {
+            DataSource = databasePath,
+            Pooling = pooling,
+        }.ToString());
         _connection.Open();
         Execute("""
             PRAGMA journal_mode=WAL;

OpenNest.Tests/Api/NestRunnerTests.cs

@@ -4,14 +4,59 @@ using System.Linq;
 using System.Threading.Tasks;
 using OpenNest.Api;
 using OpenNest.Converters;
+using OpenNest.Engine.Jobs;
 using OpenNest.Geometry;
 using OpenNest.IO;
-using OpenNest.Engine.Jobs;
 
 namespace OpenNest.Tests.Api;
 
 public class NestRunnerTests
 {
+    [Fact]
+    public async Task ExplicitPricesSelectCheaperStockAndSurviveArchive()
+    {
+        var path = CreateTempSquareDxf(4, 4);
+        var archive = Path.ChangeExtension(path, ".nestquote");
+        try
+        {
+            var response = await NestRunner.RunAsync(new NestRequest
+            {
+                Engine = "Rectangles",
+                Parts = [new NestRequestPart { DxfPath = path, Quantity = 1 }],
+                Plates = [new NestRequestPlate { Id = "small", Size = new Size(10, 10), Quantity = 1, Cost = 50 },
+                    new NestRequestPlate { Id = "large", Size = new Size(12, 12), Quantity = 1, Cost = 7 }],
+            });
+            Assert.Equal(NestValidationStatus.Valid, response.ValidationStatus);
+            Assert.Equal("large", Assert.Single(response.PlateStockMappings).StockId);
+            Assert.Equal("supplied-cost", response.Costs.Basis);
+            Assert.Equal(7, response.Costs.GrossTotal);
+            Assert.Equal(7, response.Costs.NetScore);
+            Assert.Equal(0, response.Costs.SalvageCredit);
+            await response.SaveAsync(archive);
+            var reopened = await NestResponse.LoadAsync(archive);
+            Assert.Equal(7, reopened.Costs.GrossTotal);
+            Assert.Equal(new[] { 50d, 7d }, reopened.Nest.PlateOptions.Select(p => p.Cost));
+            Assert.Equal(7, reopened.Request.Plates[1].Cost);
+        }
+        finally
+        {
+            File.Delete(path);
+            File.Delete(archive);
+        }
+    }
+
+    [Fact]
+    public async Task MixedCostsFailBeforeImport()
+    {
+        var error = await Assert.ThrowsAsync<ArgumentException>(() => NestRunner.RunAsync(new NestRequest
+        {
+            Parts = [new NestRequestPart { DxfPath = "missing.dxf", Quantity = 1 }],
+            Plates = [new NestRequestPlate { Id = "priced", Size = new Size(10, 10), Cost = 2 },
+                new NestRequestPlate { Id = "missing", Size = new Size(12, 12) }],
+        }));
+        Assert.Contains("Missing: missing", error.Message);
+    }
+
     [Fact]
     public async Task RunAsync_LegacySheetSize_UsesUnlimitedLegacyStockAndDerivedPartId()
     {

OpenNest.Tests/CuttingPlanning/BestEffortCuttingPlanTests.cs

@@ -0,0 +1,281 @@
+using OpenNest.CNC;
+using OpenNest.CNC.CuttingPlanning;
+using OpenNest.Engine.CuttingPlanning;
+using OpenNest.Geometry;
+
+namespace OpenNest.Tests.CuttingPlanning;
+
+public class BestEffortCuttingPlanTests
+{
+    [Fact]
+    public void TouchingContours_OfferAPreviewWithoutChangingTheDrawing()
+    {
+        var part = TouchingContours();
+        var plate = Plate(part);
+        var original = OwnedProgramCopy.Copy(part.BaseDrawing.Program);
+        var strict = CuttingPlanService.Plan(CuttingPlanRequest.ForPlate(plate,
+            confirmedParameters: ExplicitContourTests.Parameters()));
+        Assert.Equal(CuttingPlanStatus.UnsupportedGeometry, strict.Status);
+
+        var proposal = CuttingPlanBatch.Capture([plate], ExplicitContourTests.Parameters(), false).Plan();
+
+        Assert.NotNull(proposal.BuildPreview(0));
+        Assert.False(proposal.CanApply);
+        Assert.False(part.HasManualLeadIns);
+        Assert.True(ProgramContent.Equal(original, part.BaseDrawing.Program));
+    }
+
+    [Fact]
+    public void UnverifiedSummary_ShowsEveryWarningBeforeAcceptance()
+    {
+        var parts = Enumerable.Range(0, 6).Select(index =>
+        {
+            var part = TouchingContours();
+            part.Offset(index * 12, 0);
+            return part;
+        }).ToArray();
+        var proposal = CuttingPlanBatch.Capture([Plate(parts)], ExplicitContourTests.Parameters(), false).Plan();
+        Assert.True(proposal.RequiresWarningAcceptance);
+        var findings = Assert.Single(proposal.Plates).Result.Findings.ToArray();
+        Assert.True(findings.Length > 5);
+        Assert.Contains(findings, finding => finding.SourceOrdinal == 5);
+        var summary = string.Join("\n", proposal.Describe("in"));
+        Assert.Contains("Part 6", summary);
+        Assert.DoesNotContain("... and", summary);
+    }
+
+    [Fact]
+    public void AcceptWarnings_InstallsOwnedProgramsAndLeavesStrictApplyClosed()
+    {
+        var part = TouchingContours();
+        var plate = Plate(part);
+        var source = OwnedProgramCopy.Copy(part.BaseDrawing.Program);
+        var pose = (part.Location, part.Rotation);
+        var proposal = CuttingPlanBatch.Capture([plate], ExplicitContourTests.Parameters(), false).Plan();
+        var result = Assert.Single(proposal.Plates).Result;
+        Assert.Equal(CuttingPlanStatus.BestEffort, result.Status);
+        Assert.False(result.IndependentlyReplayed);
+        Assert.True(proposal.RequiresWarningAcceptance);
+        Assert.Contains(result.Findings, f => f.Message.Contains("Material boundaries"));
+        Assert.Contains("unverified", string.Join("\n", proposal.Describe("in")));
+        Assert.Equal(CuttingCommitStatus.InvalidInput, proposal.Apply().Status);
+        Assert.Equal(CuttingCommitStatus.InvalidInput, CuttingPlanService.Apply([result]).Status);
+        var generated = Assert.Single(result.ProposedOrder);
+        Assert.True(generated.IsRegenerated);
+        Assert.Equal(3, generated.ContourChoices.Count);
+        Assert.Equal(2, generated.ContourChoices[^1].ContourOrdinal);
+        var originalCuts = ExecutionMotionReader.ReadSupported(source, part.Location, null).Motions
+            .Where(m => !m.Rapid && m.Layer is LayerType.Cut or LayerType.Display).Sum(m => m.Length);
+        var emittedCuts = ExecutionMotionReader.ReadSupported(generated.CopyProgram(), part.Location, null).Motions
+            .Where(m => !m.Rapid && m.Layer is LayerType.Cut or LayerType.Display).Sum(m => m.Length);
+        Assert.Equal(originalCuts, emittedCuts, 8);
+        var copy = generated.CopyProgram();
+        copy.Codes.Clear();
+
+        Assert.Equal(CuttingCommitStatus.Applied, proposal.Apply(acceptWarnings: true).Status);
+
+        Assert.True(part.HasManualLeadIns);
+        Assert.True(ProgramContent.Equal(generated.CopyProgram(), part.Program));
+        Assert.True(ProgramContent.Equal(source, part.BaseDrawing.Program));
+        Assert.Equal(pose, (part.Location, part.Rotation));
+        Assert.Equal(CuttingCommitStatus.Stale, proposal.Apply(acceptWarnings: true).Status);
+    }
+
+    [Theory]
+    [InlineData("null")]
+    [InlineData("unknown")]
+    [InlineData("cycle")]
+    [InlineData("nonfinite")]
+    [InlineData("open")]
+    [InlineData("suppressed")]
+    public void UnreadableOrUnrepresentableInput_IsNeverWaived(string failure)
+    {
+        var part = TouchingContours();
+        var plate = Plate(part);
+        var program = part.BaseDrawing.Program;
+        switch (failure)
+        {
+            case "null": program.Codes = null; break;
+            case "unknown": program.Codes.Add(new CustomMove()); break;
+            case "cycle": program.Codes.Add(new SubProgramCall { Program = program }); break;
+            case "nonfinite": part.Location = new Vector(double.NaN, 1); break;
+            case "open": program.Codes.RemoveAt(program.Codes.Count - 1); break;
+            case "suppressed": program.Codes.OfType<Motion>().First().Suppressed = true; break;
+        }
+        var proposal = CuttingPlanBatch.Capture([plate], ExplicitContourTests.Parameters(), false).Plan();
+        Assert.False(proposal.CanApplyWithWarnings);
+        Assert.Null(proposal.BuildPreview(0));
+        Assert.Equal(CuttingCommitStatus.InvalidInput, proposal.Apply(acceptWarnings: true).Status);
+        Assert.False(part.HasManualLeadIns);
+    }
+
+    [Fact]
+    public void MixedBatch_StaleOrCancelledChangesNothing()
+    {
+        var imperfect = TouchingContours();
+        var clean = new Part(new Drawing("clean", ExplicitContourTests.Square(false)), new Vector(1, 1));
+        var plates = new[] { Plate(clean), Plate(imperfect) };
+        var originals = new[] { clean.Program, imperfect.Program };
+        var batch = CuttingPlanBatch.Capture(plates, ExplicitContourTests.Parameters(), false);
+        var proposal = batch.Plan();
+        Assert.True(proposal.RequiresWarningAcceptance);
+        using var cancelled = new CancellationTokenSource();
+        cancelled.Cancel();
+        Assert.Equal(CuttingCommitStatus.Cancelled, proposal.Apply(true, cancelled.Token).Status);
+        Assert.False(batch.Plan(token: cancelled.Token).CanApplyWithWarnings);
+        imperfect.Offset(1, 0);
+        Assert.Null(proposal.BuildPreview(1));
+        Assert.Equal(CuttingCommitStatus.Stale, proposal.Apply(acceptWarnings: true).Status);
+        Assert.Equal(originals, plates.SelectMany(p => p.Parts).Select(p => p.Program));
+        Assert.All(plates, p => Assert.Null(p.CuttingParameters));
+    }
+
+    [Fact]
+    public void LockedPart_KeepsExactProgramWhileOtherPartsRegenerate()
+    {
+        var part = TouchingContours();
+        part.LeadInsLocked = true;
+        var program = part.Program;
+        var other = new Part(new Drawing("clean", ExplicitContourTests.Square(false)), new Vector(20, 1));
+        var proposal = CuttingPlanBatch.Capture([Plate(part, other)], ExplicitContourTests.Parameters(), false).Plan();
+        Assert.True(proposal.RequiresWarningAcceptance);
+        Assert.False(proposal.Plates[0].Result.ProposedOrder[0].IsRegenerated);
+        Assert.Equal(CuttingCommitStatus.Applied, proposal.Apply(true).Status);
+        Assert.Same(program, part.Program);
+        Assert.True(part.LeadInsLocked);
+        Assert.True(other.HasManualLeadIns);
+    }
+
+    [Fact]
+    public void KnownPartOverlap_StillBlocksTheWholeBatch()
+    {
+        var first = new Part(new Drawing("first", ExplicitContourTests.Square(false)), new Vector(1, 1));
+        var second = new Part(new Drawing("second", ExplicitContourTests.Square(false)), new Vector(6, 6));
+        var proposal = CuttingPlanBatch.Capture([Plate(TouchingContours()), Plate(first, second)],
+            ExplicitContourTests.Parameters(), false).Plan();
+        Assert.False(proposal.CanApplyWithWarnings);
+        Assert.Equal(CuttingCommitStatus.InvalidInput, proposal.Apply(true).Status);
+        Assert.False(first.HasManualLeadIns);
+    }
+
+    [Theory]
+    [InlineData(false)]
+    [InlineData(true)]
+    public void ProvenCutoffDependencies_AreNotWaived(bool keepOrder)
+    {
+        var part = TouchingContours();
+        var cutProgram = new Program();
+        cutProgram.MoveTo(20, 0); cutProgram.LineTo(20, 20);
+        var cutoff = new Part(new Drawing("cutoff", cutProgram) { IsCutOff = true });
+        var plate = Plate(part, cutoff); // An orphaned cutoff must precede all ordinary parts.
+        var proposal = CuttingPlanBatch.Capture([plate], ExplicitContourTests.Parameters(), keepOrder).Plan();
+        if (keepOrder)
+        {
+            Assert.False(proposal.CanApplyWithWarnings);
+            Assert.Equal(CuttingCommitStatus.InvalidInput, proposal.Apply(true).Status);
+        }
+        else
+        {
+            Assert.True(proposal.CanApplyWithWarnings);
+            Assert.Same(cutoff, proposal.Plates[0].Result.ProposedOrder[0].SourcePart);
+            Assert.False(proposal.Plates[0].Result.ProposedOrder[0].IsRegenerated);
+        }
+    }
+
+    [Fact]
+    public void SelfIntersectingClosedContour_StillGetsEveryCutAndALead()
+    {
+        var program = new Program();
+        program.MoveTo(0, 0); program.LineTo(8, 8); program.LineTo(0, 8);
+        program.LineTo(8, 0); program.LineTo(0, 0);
+        var part = new Part(new Drawing("crossed contour", program), new Vector(1, 1));
+        var proposal = CuttingPlanBatch.Capture([Plate(part)], ExplicitContourTests.Parameters(), false).Plan();
+        Assert.True(proposal.RequiresWarningAcceptance);
+        var generated = Assert.Single(proposal.Plates[0].Result.ProposedOrder);
+        Assert.True(generated.IsRegenerated);
+        Assert.Single(generated.ContourChoices);
+        var moves = ExecutionMotionReader.ReadSupported(generated.CopyProgram(), part.Location, null).Motions;
+        Assert.Contains(moves, m => m.Layer == LayerType.Leadin);
+        var original = ExecutionMotionReader.ReadSupported(program, part.Location, null).Motions;
+        Assert.Equal(original.Where(m => !m.Rapid).Sum(m => m.Length),
+            moves.Where(m => !m.Rapid && m.Layer is LayerType.Cut or LayerType.Display).Sum(m => m.Length), 8);
+    }
+
+    [Fact]
+    public void ProvenNestedPart_PrecedesItsHostEvenWithAnImperfectNeighbour()
+    {
+        var hostProgram = ExplicitContourTests.Square(false);
+        hostProgram.MoveTo(2, 2); hostProgram.LineTo(8, 2); hostProgram.LineTo(8, 8);
+        hostProgram.LineTo(2, 8); hostProgram.LineTo(2, 2);
+        var host = new Part(new Drawing("host", hostProgram));
+        var innerProgram = new Program();
+        innerProgram.MoveTo(0, 0); innerProgram.LineTo(0, 1); innerProgram.LineTo(1, 1);
+        innerProgram.LineTo(1, 0); innerProgram.LineTo(0, 0);
+        var inner = new Part(new Drawing("insert", innerProgram), new Vector(4, 4));
+        var imperfect = TouchingContours();
+        imperfect.Offset(20, 0);
+        var proposal = CuttingPlanBatch.Capture([Plate(host, inner, imperfect)],
+            ExplicitContourTests.Parameters(), false).Plan();
+        Assert.True(proposal.RequiresWarningAcceptance, string.Join("\n", proposal.Describe("in")));
+        var order = proposal.Plates[0].Result.ProposedOrder.Select(p => p.SourcePart).ToList();
+        Assert.True(order.IndexOf(inner) < order.IndexOf(host));
+    }
+
+    [Fact]
+    public void BestEffortInstallFailure_RollsBackEveryPlate()
+    {
+        var parts = new[] { TouchingContours(), TouchingContours() };
+        var plates = parts.Select(p => Plate(p)).ToArray();
+        var originals = parts.Select(p => p.Program).ToArray();
+        var proposal = CuttingPlanBatch.Capture(plates, ExplicitContourTests.Parameters(), false).Plan();
+        Assert.True(proposal.RequiresWarningAcceptance);
+        var commit = CuttingPlanService.Apply(proposal.Plates.Select(p => p.Result), default,
+            (plate, _) => { if (ReferenceEquals(plate, plates[1])) throw new InvalidOperationException("test install fault"); },
+            acceptUnverified: true);
+        Assert.Equal(CuttingCommitStatus.Failed, commit.Status);
+        Assert.Equal(originals, parts.Select(p => p.Program));
+        Assert.All(parts, p => Assert.False(p.HasManualLeadIns));
+    }
+
+    [SkippableTheory]
+    [InlineData(0)]
+    [InlineData(45)]
+    public void RealDxf_PlansAndAppliesWithoutChangingTheDrawing(double degrees)
+    {
+        var path = TestConfig.GetExistingPath("BestEffortDxfPath");
+        Skip.If(path == null, "BestEffortDxfPath not configured in test-config.json or file not found");
+        var drawing = OpenNest.IO.CadImporter.ImportDrawing(path);
+        var part = new Part(drawing, new Vector(1, 1));
+        part.Rotate(degrees * System.Math.PI / 180);
+        var plate = Plate(part);
+        var source = OwnedProgramCopy.Copy(drawing.Program);
+        var proposal = CuttingPlanBatch.Capture([plate], ExplicitContourTests.Parameters(), false).Plan();
+        Assert.True(proposal.CanApplyWithWarnings, string.Join("\n", proposal.Describe("in")));
+        Assert.NotNull(proposal.BuildPreview(0));
+        Assert.True(Assert.Single(proposal.Plates[0].Result.ProposedOrder).IsRegenerated);
+        Assert.Equal(CuttingCommitStatus.Applied, proposal.Apply(true).Status);
+        Assert.True(ProgramContent.Equal(source, drawing.Program));
+        Assert.True(part.HasManualLeadIns);
+    }
+
+    private sealed class CustomMove : LinearMove { }
+
+    internal static Part TouchingContours()
+    {
+        var program = ExplicitContourTests.Square(false);
+        // Two ordinary holes share an edge: closed executable contours, ambiguous material.
+        program.MoveTo(2, 2); program.LineTo(4, 2); program.LineTo(4, 4);
+        program.LineTo(2, 4); program.LineTo(2, 2);
+        program.MoveTo(4, 2); program.LineTo(6, 2); program.LineTo(6, 4);
+        program.LineTo(4, 4); program.LineTo(4, 2);
+        return new Part(new Drawing("touching contours", program), new Vector(1, 1));
+    }
+
+    internal static Plate Plate(params Part[] parts)
+    {
+        var plate = new Plate(new Size(100, 100));
+        foreach (var part in parts)
+            plate.Parts.Add(part);
+        return plate;
+    }
+}

OpenNest.Tests/CuttingPlanning/ContourEntryCandidateTests.cs

@@ -310,6 +310,36 @@ public class ContourEntryCandidateTests
         Assert.All(near, c => Assert.True(c.Kind > AutomaticEntryKind.TangentJoint));
     }
 
+    [Fact]
+    public void NearCornerOnRoundedJointStaysOnItsSelectedLine()
+    {
+        // Native contour joints can differ within the accepted closure tolerance. The
+        // preceding edge's corner is off the following edge by one micron, while the
+        // near-corner entry must lie on the following edge itself.
+        var shape = new Shape();
+        shape.Entities.Add(new Line(0, 0, 10, 0));
+        shape.Entities.Add(new Line(10, 0, 10, 10));
+        shape.Entities.Add(new Line(10, 10.000001, 0, 10.000001));
+        shape.Entities.Add(new Line(0, 10.000001, 0, 0));
+        shape.UpdateBounds();
+        // Capture constructs this exact owned native shape after program conversion;
+        // build it directly to characterize its legal, sub-tolerance joint discrepancy.
+        var constructor = typeof(PreparedContours).GetConstructor(
+            System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance,
+            null, [typeof(Shape[]), typeof(List<Entity>), typeof(OpenNest.CNC.CuttingStrategy.CuttingParameters)], null);
+        Assert.NotNull(constructor);
+        var prepared = (PreparedContours)constructor.Invoke([
+            new[] { shape }, new List<Entity>(), ExplicitContourTests.Parameters()]);
+        var near = prepared.AutomaticEntryCandidatesWithFallbacks(0)
+            .Where(c => c.Kind == AutomaticEntryKind.NearCorner).ToList();
+        Assert.NotEmpty(near);
+        Assert.All(near, c => Assert.Equal(c.Choice.Point,
+            prepared.Entry(c.Choice.ContourOrdinal, c.Choice.EntityOrdinal, c.Choice.Point).Point));
+        Assert.Contains(near, c => c.Choice.EntityOrdinal == 2 &&
+            System.Math.Abs(c.Choice.Point.Y - 10.000001) < 1e-10);
+        Assert.Throws<ArgumentException>(() => prepared.Entry(0, 2, new Vector(9.4, 10)));
+    }
+
     [Fact]
     public void ShortEdge_OmitsNearCornerInsteadOfExtrapolating()
     {

OpenNest.Tests/CuttingPlanning/ContourEntryFeasibilityTests.cs

@@ -126,7 +126,7 @@ public class ContourEntryFeasibilityTests
 
         // Nothing to certify means the validator passes vacuously — the emitted program
         // carries no lead motion at all, so this verdict certifies no lead and the
-        // complete-plan missing-lead check still has to run later. The adapter must not
+        // complete-plan rapid/contour checks still have to run later. The adapter must not
         // silently drop the distinction: consumers can see it is vacuous by counting leads.
         Assert.True(verdict.IsClear);
         var motions = ExecutionMotionReader.Read(prepared.Emit(new[] { choice }), At, null, default).Motions;

OpenNest.Tests/CuttingPlanning/CuttingPlanBatchTests.cs

@@ -45,7 +45,9 @@ public class CuttingPlanBatchTests
         var nest = new Nest();
         var ready = Plate(nest, Clean("open", 1, 1));
         var locked = Clean("locked", 1, 1);
-        locked.LeadInsLocked = true; // Locked programs never regenerate: no lead-in is a conflict.
+        var crossing = OwnedProgramCopy.Copy(locked.Program);
+        crossing.MoveTo(5, 5); // Rapid enters the already completed square.
+        Assert.True(locked.RestoreLeadInProgram(crossing, true));
         var blocked = Plate(nest, locked);
         var readyProgram = ready.Parts[0].Program;
 
@@ -90,6 +92,10 @@ public class CuttingPlanBatchTests
         var text = string.Join("\n", proposal.Describe("in"));
         Assert.Contains("Plate 1: blocked: parts overlap or could not be checked for overlap.", text);
         Assert.Contains("- Part 1 (first) overlaps part 2 (second).", text);
+        var row = Assert.Single(proposal.DiagnosticRows());
+        Assert.Equal((0, 1, 1, 2),
+            (row.PlateIndex, row.PlateNumber, row.PartNumber, row.OtherPartNumber));
+        Assert.Contains("overlaps part 2", row.Message);
         Assert.Equal(CuttingCommitStatus.InvalidInput, proposal.Apply().Status);
         Assert.Equal(programs, plate.Parts.Select(p => p.Program));
         Assert.All(plate.Parts, part => Assert.False(part.HasManualLeadIns));
@@ -144,6 +150,63 @@ public class CuttingPlanBatchTests
         Assert.Null(proposal.BuildPreview(0));
     }
 
+    [Fact]
+    public void PlanReorder_ShortPassReady_RetainsReplayedApplicableProposal()
+    {
+        var plate = Plate(new Nest(), Clean("first", 1, 1), Clean("second", 12, 1));
+        var snapshot = CuttingPlanService.Capture(CuttingPlanRequest.ForPlate(plate,
+            confirmedParameters: ExplicitContourTests.Parameters()));
+        var full = CuttingPlanService.Plan(snapshot);
+        var result = CuttingPlanBatch.PlanReorder(snapshot, CancellationToken.None);
+
+        Assert.Equal(CuttingPlanStatus.Ready, result.Status);
+        Assert.True(result.IndependentlyReplayed);
+        Assert.True(result.Expansions < full.Expansions,
+            $"Short pass {result.Expansions}, full {full.Expansions}");
+        Assert.InRange(result.Expansions, 1, CuttingPlanBatch.FirstPassBudget - 1);
+        Assert.Equal(2, result.ProposedOrder.Count);
+        Assert.All(plate.Parts, part => Assert.False(part.HasManualLeadIns));
+        Assert.Equal(CuttingCommitStatus.Applied, CuttingPlanService.Apply([result]).Status);
+    }
+
+    [Fact]
+    public void PlanReorder_ShortPassExhausted_UsesFullCapAndOriginalBudget()
+    {
+        var plate = Plate(new Nest(), Grid(4));
+        var snapshot = CuttingPlanService.Capture(CuttingPlanRequest.ForPlate(plate,
+            confirmedParameters: ExplicitContourTests.Parameters()));
+        var full = CuttingPlanService.Plan(snapshot);
+        var recovered = CuttingPlanBatch.PlanReorder(snapshot, CancellationToken.None, firstPassBudget: 1);
+
+        Assert.Equal(CuttingPlanStatus.Ready, full.Status);
+        Assert.Equal(CuttingPlanStatus.Ready, recovered.Status);
+        Assert.True(recovered.IndependentlyReplayed);
+        Assert.Equal(full.Expansions, recovered.Expansions);
+        Assert.Equal(full.RapidDistance, recovered.RapidDistance);
+        Assert.Equal(full.ProposedOrder.Select(p => p.SourceOrdinal), recovered.ProposedOrder.Select(p => p.SourceOrdinal));
+        for (var i = 0; i < full.ProposedOrder.Count; i++)
+            Assert.True(ProgramContent.Equal(full.ProposedOrder[i].CopyProgram(), recovered.ProposedOrder[i].CopyProgram()));
+        Assert.All(plate.Parts, part => Assert.False(part.HasManualLeadIns));
+    }
+
+    [Fact]
+    public void PlanReorder_CancelledDuringShortPass_DoesNotRetryOrMutate()
+    {
+        var plate = Plate(new Nest(), Clean("first", 1, 1), Clean("second", 12, 1));
+        using var cancellation = new CancellationTokenSource();
+        var observations = 0;
+        var request = new CuttingPlanRequest(plate.Parts, confirmedParameters: ExplicitContourTests.Parameters())
+        { ExpansionObserver = _ => { observations++; cancellation.Cancel(); } };
+        var snapshot = CuttingPlanService.Capture(request);
+
+        var result = CuttingPlanBatch.PlanReorder(snapshot, cancellation.Token);
+
+        Assert.Equal(CuttingPlanStatus.Cancelled, result.Status);
+        Assert.Equal(1, observations);
+        Assert.Empty(result.ProposedOrder);
+        Assert.All(plate.Parts, part => Assert.False(part.HasManualLeadIns));
+    }
+
     [Fact]
     public void Plan_FreeSearchOutOfBudget_KeepsTheCurrentOrderAndSaysSo()
     {
@@ -253,7 +316,9 @@ public class CuttingPlanBatchTests
         var nest = new Nest();
         var ready = Plate(nest, Clean("a", 1, 1));
         var locked = Clean("locked", 1, 1);
-        locked.LeadInsLocked = true;
+        var crossing = OwnedProgramCopy.Copy(locked.Program);
+        crossing.MoveTo(5, 5); // Rapid enters the already completed square.
+        Assert.True(locked.RestoreLeadInProgram(crossing, true));
         var blocked = Plate(nest, locked);
         var proposal = CuttingPlanBatch.Capture([ready, blocked], ExplicitContourTests.Parameters(), false).Plan();
         Assert.True(proposal.Plates[0].IsReady);

OpenNest.Tests/CuttingPlanning/CuttingPlanMessageTests.cs

@@ -8,77 +8,91 @@ namespace OpenNest.Tests.CuttingPlanning;
 
 public class CuttingPlanMessageTests
 {
+    [Fact]
+    public void Describe_MixedBestEffortAndOpenContour_CountsOnlyBlockedPlateAndExplainsGap()
+    {
+        var open = new OpenNest.CNC.Program();
+        open.MoveTo(0, 0);
+        open.LineTo(10, 0);
+        open.LineTo(10, 10);
+        open.LineTo(0, 10);
+        open.LineTo(0, 0.000002);
+        var part = new Part(new Drawing("open perimeter", open));
+        var original = OwnedProgramCopy.Copy(part.BaseDrawing.Program);
+        var plates = new[]
+        {
+            BestEffortCuttingPlanTests.Plate(BestEffortCuttingPlanTests.TouchingContours()),
+            BestEffortCuttingPlanTests.Plate(part),
+        };
+
+        var proposal = CuttingPlanBatch.Capture(plates, ExplicitContourTests.Parameters(), false).Plan();
+        var text = string.Join("\n", proposal.Describe("in"));
+
+        Assert.StartsWith("Apply is unavailable: 1 of 2 plates could not be planned.", text);
+        Assert.Contains("Plate 1: best-effort, unverified.", text);
+        Assert.Contains("Plate 2: blocked:", text);
+        Assert.Contains("contour 1 is open: endpoint gap 2E-06 model units", text);
+        Assert.Contains("closure tolerance 1E-06", text);
+        Assert.Contains("Review the source contour in the drawing editor", text);
+        Assert.False(proposal.CanApplyWithWarnings);
+        Assert.Equal(CuttingCommitStatus.InvalidInput, proposal.Apply(true).Status);
+        Assert.True(ProgramContent.Equal(original, part.BaseDrawing.Program));
+        Assert.All(plates.SelectMany(p => p.Parts), p => Assert.False(p.HasManualLeadIns));
+    }
+
     [Theory]
     [InlineData(false, false)]
     [InlineData(false, true)]
     [InlineData(true, false)]
     [InlineData(true, true)]
-    public void Describe_MissingOrZeroLengthLead_ExplainsSettingsWithoutBlamingSearch(bool keepOrder, bool zeroLength)
+    public void Describe_NoneIsSupportedButDegenerateLeadMotionStillRefuses(bool keepOrder, bool zeroLength)
     {
         var part = new Part(new Drawing("sample", ExplicitContourTests.Square(false)), new Vector(1, 1));
-        var plate = new Nest().CreatePlate();
+        var plate = BestEffortCuttingPlanTests.Plate(part);
-        plate.Size = new Size(100, 100);
+        var original = OwnedProgramCopy.Copy(part.Program);
-        plate.Parts.Add(part);
-        var program = part.Program;
-        var original = OwnedProgramCopy.Copy(program);
         var settings = new CuttingParameters();
         if (zeroLength)
             settings.ExternalLeadIn = new LineLeadIn { Length = 0, ApproachAngle = 90 };
 
         var proposal = CuttingPlanBatch.Capture([plate], settings, keepOrder).Plan();
 
+        if (zeroLength)
+        {
             Assert.False(proposal.CanApply);
-        var result = Assert.Single(proposal.Plates).Result;
+            Assert.Contains("Lead motion is missing, degenerate or inconsistent", string.Join("\n", proposal.Describe("in")));
-        Assert.Equal(CuttingPlanStatus.NoSolutionWithinBudget, result.Status);
-        Assert.Contains(result.Findings, f => f.Kind == PostVerificationKind.MissingLeadIn);
-        var text = string.Join("\n", proposal.Describe("in"));
-        Assert.Contains("Plate 1: blocked: missing or zero-length lead-in.", text);
-        Assert.Contains("Open Cutting Settings...", text);
-        Assert.Contains("other than None", text);
-        Assert.Contains("nonzero length", text);
-        Assert.Contains("Part 1 (sample):", text);
-        Assert.Contains("Cutting contour 1", text);
-        Assert.DoesNotContain("search limit", text);
-        Assert.Equal(CuttingCommitStatus.InvalidInput, proposal.Apply().Status);
-        Assert.Same(program, part.Program);
             Assert.True(ProgramContent.Equal(original, part.Program));
-        Assert.Null(plate.CuttingParameters);
+            return;
-        Assert.False(part.HasManualLeadIns);
+        }
 
-        // Choosing valid settings fixes the refusal; reporting never changes settings or bypasses checks.
+        Assert.True(proposal.CanApply, string.Join("\n", proposal.Describe("in")));
-        var ready = CuttingPlanBatch.Capture([plate], ExplicitContourTests.Parameters(), keepOrder).Plan();
+        var result = Assert.Single(proposal.Plates).Result;
-        Assert.True(ready.CanApply, string.Join("\n", ready.Describe("in")));
+        Assert.True(result.IndependentlyReplayed);
-        Assert.True(Assert.Single(ready.Plates).Result.IndependentlyReplayed);
+        Assert.DoesNotContain(result.Findings, f => f.Kind == PostVerificationKind.MissingLeadIn);
-        Assert.DoesNotContain("missing or zero-length", string.Join("\n", ready.Describe("in")));
+        Assert.Contains("Plate 1: ready.", string.Join("\n", proposal.Describe("in")));
-        Assert.Same(program, part.Program);
+        var output = Assert.Single(result.ProposedOrder).CopyProgram();
+        Assert.DoesNotContain(ExecutionMotionReader.ReadSupported(output, part.Location, null).Motions,
+            m => m.Layer == OpenNest.CNC.LayerType.Leadin && m.Length > 0);
         Assert.True(ProgramContent.Equal(original, part.Program));
+        Assert.Equal(CuttingCommitStatus.Applied, proposal.Apply().Status);
     }
 
     [Fact]
-    public void Describe_LockedProgramWithoutLead_ExplainsThatSettingsCannotRegenerateIt()
+    public void Describe_LockedProgramWithoutLead_IsReadyAndKeepsItsProgram()
     {
         var part = new Part(new Drawing("locked sample", ExplicitContourTests.Square(false)), new Vector(1, 1))
         {
             LeadInsLocked = true,
         };
-        var plate = new Nest().CreatePlate();
+        var plate = BestEffortCuttingPlanTests.Plate(part);
-        plate.Size = new Size(100, 100);
-        plate.Parts.Add(part);
         var program = part.Program;
-
         var proposal = CuttingPlanBatch.Capture([plate], ExplicitContourTests.Parameters(), false).Plan();
 
-        Assert.Equal(CuttingPlanStatus.ConstraintConflict, Assert.Single(proposal.Plates).Result.Status);
+        Assert.True(proposal.CanApply, string.Join("\n", proposal.Describe("in")));
-        Assert.False(proposal.CanApply);
+        Assert.False(Assert.Single(proposal.Plates[0].Result.ProposedOrder).IsRegenerated);
-        var text = string.Join("\n", proposal.Describe("in"));
+        Assert.Equal(CuttingCommitStatus.Applied, proposal.Apply().Status);
-        Assert.Contains("missing or zero-length lead-in", text);
-        Assert.Contains("If the affected part is locked, edit its lead-ins or unlock it before replanning.", text);
-        Assert.Contains("Part 1 (locked sample):", text);
-        Assert.Equal(CuttingCommitStatus.InvalidInput, proposal.Apply().Status);
         Assert.True(part.LeadInsLocked);
         Assert.Same(program, part.Program);
     }
-
     [Fact]
     public void Describe_LeadHitsNeighbour_SuggestsSpacingOrShorterLeadWithoutAllowingApply()
     {

OpenNest.Tests/CuttingPlanning/CuttingPlanServiceTests.cs

@@ -126,9 +126,24 @@ public class CuttingPlanServiceTests
         Assert.Equal(beforeCodes, program.Codes?.ToArray());
     }
 
+    [Fact]
+    public void FixedProgramWithoutLead_IsReadyAndReplayed()
+    {
+        var part = Fixture()[0];
+        part.Program.Codes.RemoveAt(1);
+        ((RapidMove)part.Program.Codes[0]).EndPoint = new Vector(4, 2);
+        var unchanged = Unchanged([part]);
+
+        var result = CuttingPlanService.Plan(new CuttingPlanRequest([part]));
+
+        Assert.Equal(CuttingPlanStatus.Ready, result.Status);
+        Assert.True(result.IndependentlyReplayed);
+        Assert.False(Assert.Single(result.ProposedOrder).IsRegenerated);
+        unchanged();
+    }
+
     [Theory]
     [InlineData("suppressed")]
-    [InlineData("missing-lead")]
     [InlineData("retention-unknown")]
     [InlineData("cutoff")]
     public void Plan_UnsupportedOrIncompleteStateIsRefused(string fault)
@@ -138,10 +153,6 @@ public class CuttingPlanServiceTests
         switch (fault)
         {
             case "suppressed": ((Motion)part.Program.Codes[2]).Suppressed = true; break;
-            case "missing-lead":
-                part.Program.Codes.RemoveAt(1);
-                ((RapidMove)part.Program.Codes[0]).EndPoint = new Vector(4, 2);
-                expected = CuttingPlanStatus.ConstraintConflict; break;
             case "retention-unknown": ((LinearMove)part.Program.Codes[^2]).EndPoint = new Vector(4, 2.25); break;
             case "cutoff": part.BaseDrawing.IsCutOff = true; break;
         }

OpenNest.Tests/CuttingPlanning/JointCuttingPlanTests.cs

@@ -4,11 +4,55 @@ using OpenNest.CNC.CuttingStrategy;
 using OpenNest.Diagnostics;
 using OpenNest.Engine.CuttingPlanning;
 using OpenNest.Geometry;
+using OpenNest.IO;
 
 namespace OpenNest.Tests.CuttingPlanning;
 
 public class JointCuttingPlanTests
 {
+    [Fact]
+    public void JointSearch_NoLeads_RepairsRapidCrossings()
+    {
+        var (part, parameters) = Crossing();
+        parameters.ExternalLeadIn = new NoLeadIn();
+        parameters.InternalLeadIn = new NoLeadIn();
+        parameters.ArcCircleLeadIn = new NoLeadIn();
+        var unchanged = Unchanged(part, parameters);
+        var source = Read(part.Program, part.Location);
+        Assert.Contains(new ReleasedContourState(reportMissingLeadIns: false).Check(source, Vector.Zero, 1),
+            f => f.Kind == PostVerificationKind.RapidCrossing);
+
+        var result = CuttingPlanService.Plan(new CuttingPlanRequest([part], confirmedParameters: parameters));
+
+        Assert.True(result.Status == CuttingPlanStatus.Ready, Describe(result));
+        Assert.True(result.IndependentlyReplayed);
+        var output = Read(Assert.Single(result.ProposedOrder).CopyProgram(), part.Location);
+        Assert.DoesNotContain(output.Motions, m => m.Layer == LayerType.Leadin);
+        Assert.Empty(new ReleasedContourState(reportMissingLeadIns: false).Check(output, Vector.Zero, 1));
+        Assert.Contains(new ReleasedContourState().Check(output, Vector.Zero, 1),
+            f => f.Kind == PostVerificationKind.MissingLeadIn);
+        unchanged();
+    }
+
+    [Fact]
+    public void JointSearch_NoLeads_ChoosesDifferentPiercesForOppositeApproaches()
+    {
+        var part = new Part(new Drawing("direct pierce", ExplicitContourTests.Square(false)));
+        var settings = new CuttingParameters();
+        var pierces = new List<Vector?>();
+        foreach (var start in new[] { new Vector(-5, 5), new Vector(15, 5) })
+        {
+            var result = CuttingPlanService.Plan(new CuttingPlanRequest([part], start, confirmedParameters: settings));
+            Assert.True(result.Status == CuttingPlanStatus.Ready, Describe(result));
+            Assert.True(result.IndependentlyReplayed);
+            var output = Read(Assert.Single(result.ProposedOrder).CopyProgram(), part.Location);
+            Assert.DoesNotContain(output.Motions, m => m.Layer == LayerType.Leadin);
+            pierces.Add(output.Motions.First(m => !m.Rapid && m.Layer is LayerType.Cut or LayerType.Display).Start);
+            Assert.Empty(new ReleasedContourState(reportMissingLeadIns: false).Check(output, start, 1));
+        }
+        Assert.NotEqual(pierces[0], pierces[1]);
+    }
+
     [Fact]
     public void JointSearch_RepairsActualCompletedHoleCrossing_WithExactReplayAndNoMutation()
     {
@@ -46,7 +90,6 @@ public class JointCuttingPlanTests
     [Theory]
     [InlineData("locked")]
     [InlineData("ineligible")]
-    [InlineData("no-valid-entry")]
     [InlineData("unsupported")]
     public void JointSearch_RefusesWithoutInstallingFallbackOrMutating(string fault)
     {
@@ -55,12 +98,6 @@ public class JointCuttingPlanTests
         var expected = CuttingPlanStatus.ConstraintConflict;
         if (fault == "locked") part.LeadInsLocked = true;
         if (fault == "ineligible") eligible = [];
-        if (fault == "no-valid-entry")
-        {
-            parameters.ArcCircleLeadIn = new NoLeadIn();
-            parameters.InternalLeadIn = parameters.ArcCircleLeadIn;
-            expected = CuttingPlanStatus.NoSolutionWithinBudget;
-        }
         if (fault == "unsupported")
         {
             part.BaseDrawing.Program.Codes.AddRange(LeadPathValidationTests.Rectangle(30, 30, 40, 40).Codes);
@@ -418,7 +455,7 @@ public class JointCuttingPlanTests
         var manual = part.HasManualLeadIns;
         var bounds = part.BoundingBox;
         var quantity = part.BaseDrawing.Quantity.Nested;
-        var length = ((LineLeadIn)parameters.ExternalLeadIn).Length;
+        var settings = CuttingParametersSerializer.Serialize(parameters);
         return () =>
         {
             Assert.Same(program, part.Program); Assert.Same(clean, part.BaseDrawing.Program);
@@ -427,7 +464,7 @@ public class JointCuttingPlanTests
             Assert.Equal(locked, part.LeadInsLocked); Assert.Equal(manual, part.HasManualLeadIns);
             Assert.Same(bounds, part.BoundingBox); Assert.Same(parameters, part.CuttingParameters);
             Assert.Equal(quantity, part.BaseDrawing.Quantity.Nested);
-            Assert.Equal(length, ((LineLeadIn)parameters.ExternalLeadIn).Length);
+            Assert.Equal(settings, CuttingParametersSerializer.Serialize(parameters));
             foreach (var sub in subs)
             {
                 Assert.Same(sub.Program, sub.c.Program); Assert.Equal(sub.text, sub.c.Program.ToString());

OpenNest.Tests/CuttingPlanning/LazyCuttingSearchTests.cs

@@ -0,0 +1,60 @@
+using OpenNest.CNC.CuttingPlanning;
+using OpenNest.Engine.CuttingPlanning;
+using OpenNest.Geometry;
+
+namespace OpenNest.Tests.CuttingPlanning;
+
+public class LazyCuttingSearchTests
+{
+    [Theory]
+    [InlineData(false)]
+    [InlineData(true)]
+    public void RankedRouteDoesNotSpendBudgetEmittingUnusedSiblings(bool preserveOrder)
+    {
+        var parts = Parts();
+        var programs = parts.Select(p => p.Program).ToArray();
+        var parameters = ExplicitContourTests.Parameters();
+        var snapshot = CuttingPlanService.Capture(new CuttingPlanRequest(parts, new Vector(-2, -2),
+            expansionBudget: 36, confirmedParameters: parameters, preservePartOrder: preserveOrder));
+        var result = CuttingPlanService.Plan(snapshot);
+        Assert.Equal(CuttingPlanStatus.Ready, result.Status);
+        Assert.True(result.IndependentlyReplayed);
+        Assert.Equal(new[] { 0, 1 }, result.ProposedOrder.Select(p => p.SourceOrdinal));
+        Assert.InRange(result.Expansions, 1, 36);
+        var replay = CuttingPlanService.ReplayPrograms(snapshot, result.ProposedOrder, 0, default);
+        Assert.Equal(CuttingPlanStatus.Ready, replay.Status);
+        Assert.True(replay.IndependentlyReplayed);
+        Assert.Equal(programs, parts.Select(p => p.Program));
+    }
+
+    [Theory]
+    [InlineData(false)]
+    [InlineData(true)]
+    public void LazyTraversalKeepsBudgetAndMidSearchCancellationFailClosed(bool preserveOrder)
+    {
+        var parts = Parts();
+        var programs = parts.Select(p => p.Program).ToArray();
+        var parameters = ExplicitContourTests.Parameters();
+        var bounded = CuttingPlanService.Plan(new CuttingPlanRequest(parts, new Vector(-2, -2),
+            expansionBudget: 1, confirmedParameters: parameters, preservePartOrder: preserveOrder));
+        Assert.Equal(CuttingPlanStatus.NoSolutionWithinBudget, bounded.Status);
+        Assert.Equal(1, bounded.Expansions);
+        Assert.Empty(bounded.ProposedOrder);
+        Assert.False(bounded.IndependentlyReplayed);
+        using var cancellation = new CancellationTokenSource();
+        var cancelled = CuttingPlanService.Plan(new CuttingPlanRequest(parts, new Vector(-2, -2),
+            confirmedParameters: parameters, preservePartOrder: preserveOrder)
+        { ExpansionObserver = n => { if (n == 10) cancellation.Cancel(); } }, cancellation.Token);
+        Assert.Equal(CuttingPlanStatus.Cancelled, cancelled.Status);
+        Assert.Equal(10, cancelled.Expansions);
+        Assert.Empty(cancelled.ProposedOrder);
+        Assert.False(cancelled.IndependentlyReplayed);
+        Assert.Equal(programs, parts.Select(p => p.Program));
+    }
+
+    private static Part[] Parts() =>
+    [
+        new(new Drawing("first", LeadPathValidationTests.Rectangle(0, 0, 10, 10)), Vector.Zero),
+        new(new Drawing("second", LeadPathValidationTests.Rectangle(0, 0, 10, 10)), new Vector(20, 0)),
+    ];
+}

OpenNest.Tests/CuttingPlanning/LeadMaterialSnapshotTests.cs

@@ -0,0 +1,137 @@
+using OpenNest.CNC;
+using OpenNest.CNC.CuttingPlanning;
+using OpenNest.Geometry;
+
+namespace OpenNest.Tests.CuttingPlanning;
+
+public class LeadMaterialSnapshotTests
+{
+    [Theory]
+    [InlineData(false, 0, 0, 0)]
+    [InlineData(true, 0, 0, 0)]
+    [InlineData(false, 0.7, 40, 20)]
+    [InlineData(true, 0.7, 40, 20)]
+    public void AdjacentArcs_IntersectionOnExtensionIsNotASelfIntersection(bool atSeam, double angle, double x, double y)
+    {
+        var program = ArcJoint(0.00005, false, atSeam);
+        program.Rotate(angle);
+        var location = new Vector(x, y);
+        var execution = ExecutionMotionReader.ReadSupported(program, location, null);
+        var arcs = execution.Motions.Where(m => m.Curve?.IsFiniteArc == true).Select(m => m.Curve!).ToArray();
+        var contacts = arcs[0].Contacts(arcs[1], out var overlap);
+        Assert.False(overlap);
+        Assert.Contains(contacts, p => arcs.Any(a => a.IsOutsideArcSpan(p)));
+
+        var material = LeadMaterialSnapshot.Capture(program, location);
+
+        Assert.True(material.IsComplete, material.Reason);
+    }
+
+    [Fact]
+    public void AdjacentArcs_RealSecondIntersectionRemainsRejected()
+    {
+        var program = ArcJoint(-0.00005, true, false);
+        var arcs = ExecutionMotionReader.ReadSupported(program, Vector.Zero, null).Motions
+            .Where(m => m.Curve?.IsFiniteArc == true).Select(m => m.Curve!).ToArray();
+        var contacts = arcs[0].Contacts(arcs[1], out var overlap);
+        Assert.False(overlap);
+        Assert.Contains(contacts, p => p.DistanceTo(Vector.Zero) > 0.00001
+            && !arcs[0].IsOutsideArcSpan(p) && !arcs[1].IsOutsideArcSpan(p));
+        var material = LeadMaterialSnapshot.Capture(program, Vector.Zero);
+
+        Assert.False(material.IsComplete);
+        Assert.Contains("Material boundaries", material.Reason);
+    }
+
+    private static Program ArcJoint(double centerOffset, bool reverseSecond, bool atSeam)
+    {
+        // Near-tangent circles meet at zero and about 0.000106 away. The native
+        // angular band of the radius-18 arc admits its extension beyond zero.
+        var first = new Vector(-18, 18);
+        var center = new Vector(centerOffset, 1);
+        var end = center + new Vector(center.DistanceTo(Vector.Zero), 0);
+        var program = new Program();
+        program.MoveTo(atSeam ? Vector.Zero : first);
+        if (!atSeam)
+            program.ArcTo(0, 0, 0, 18, RotationType.CCW);
+        program.ArcTo(end.X, end.Y, center.X, center.Y, reverseSecond ? RotationType.CW : RotationType.CCW);
+        program.LineTo(first);
+        if (atSeam)
+            program.ArcTo(0, 0, 0, 18, RotationType.CCW);
+        return program;
+    }
+
+    [Theory]
+    [InlineData(false)]
+    [InlineData(true)]
+    public void RoundedCornerContact_RoundingAtAdjacentEndpointIsAccepted(bool atSeam)
+    {
+        // Rounded imported corner: its native tangent contact falls 1.52e-8
+        // from the authored arc/line joint. Exercise both consecutive and seam adjacency.
+        var program = new Program();
+        var start = new Vector(120.509177, 14.879559);
+        program.MoveTo(start);
+        program.Codes.Add(new ArcMove(new Vector(120.5, 14.9375),
+            new Vector(120.6875000024, 14.9374999848), RotationType.CW));
+        program.LineTo(120.5, 28.5625);
+        program.Codes.Add(new ArcMove(new Vector(120.6875, 28.75),
+            new Vector(120.6875, 28.5625), RotationType.CW));
+        program.LineTo(127.6875, 28.75);
+        program.Codes.Add(new ArcMove(new Vector(127.875, 28.5625),
+            new Vector(127.6875, 28.5625), RotationType.CW));
+        program.LineTo(127.875, 14.9375);
+        program.Codes.Add(new ArcMove(new Vector(127.6875, 14.75),
+            new Vector(127.6875, 14.9375), RotationType.CW));
+        program.LineTo(120.6875, 14.75);
+        program.Codes.Add(new ArcMove(start,
+            new Vector(120.6874999967, 14.9375000024), RotationType.CW));
+        if (atSeam)
+        {
+            var first = program.Codes[1];
+            program.Codes.RemoveAt(1);
+            program.Codes.Add(first);
+            program.Codes[0] = new RapidMove(120.5, 14.9375);
+        }
+
+        var material = LeadMaterialSnapshot.Capture(program, Vector.Zero);
+
+        Assert.True(material.IsComplete, material.Reason);
+    }
+
+    [Theory]
+    [InlineData(false)]
+    [InlineData(true)]
+    public void CrossingOrRetracedBoundary_RemainsRejected(bool retraced)
+    {
+        var program = new Program();
+        program.MoveTo(0, 0);
+        program.LineTo(8, 8);
+        if (retraced)
+        {
+            program.LineTo(4, 4);
+            program.LineTo(0, 8);
+        }
+        else
+        {
+            program.LineTo(0, 8);
+            program.LineTo(8, 0);
+        }
+        program.LineTo(0, 0);
+
+        var material = LeadMaterialSnapshot.Capture(program, Vector.Zero);
+
+        Assert.False(material.IsComplete);
+        Assert.Contains("Material boundaries", material.Reason);
+    }
+
+    [Fact]
+    public void SeparateTouchingHoles_RemainRejected()
+    {
+        var part = BestEffortCuttingPlanTests.TouchingContours();
+
+        var material = LeadMaterialSnapshot.Capture(part.BaseDrawing.Program, Vector.Zero);
+
+        Assert.False(material.IsComplete);
+        Assert.Contains("Material boundaries", material.Reason);
+    }
+}

OpenNest.Tests/CuttingPlanning/NativeContactRegressionTests.cs

@@ -119,6 +119,50 @@ public class NativeContactRegressionTests
         Assert.Throws<NotSupportedException>(() => circle.Contacts(line, out _));
     }
 
+    [Fact]
+    public void ReusedNativeCurves_KeepContactAndContainmentVerdictsAcrossCallsAndThreads()
+    {
+        var lineStart = new Vector(-2, 0);
+        var lineEnd = new Vector(2, 0);
+        var arcCenter = new Vector(0, 0.003);
+        var arcStart = new Vector(0.003, 0.003);
+        var circleCenter = new Vector(0, 0);
+        var circleStart = new Vector(0.003, 0);
+        var line = PostVerificationGeometry.Curve.Create(lineStart, lineEnd, null, false);
+        var arc = PostVerificationGeometry.Curve.Create(arcStart, new Vector(-0.003, 0.003), arcCenter, false);
+        var circle = PostVerificationGeometry.Curve.Create(circleStart, circleStart, circleCenter, false);
+        var pairs = new[] { (line, arc), (arc, line), (line, circle), (circle, line), (arc, circle), (circle, arc) };
+        var probes = new[] { Vector.Zero, new Vector(0.003, 0), new Vector(0, 0.006) };
+
+        string Observe(PostVerificationGeometry.Curve a, PostVerificationGeometry.Curve b)
+        {
+            var inside = string.Join(",", probes.Select(p => $"{a.Contains(p)}:{b.Contains(p)}"));
+            try
+            {
+                var contacts = a.Contacts(b, out var overlap);
+                return $"{inside}|{overlap}|" + string.Join(";", contacts.Select(p =>
+                    $"{BitConverter.DoubleToInt64Bits(p.X)}:{BitConverter.DoubleToInt64Bits(p.Y)}"));
+            }
+            catch (Exception ex) when (ex is ArgumentException or NotSupportedException)
+            {
+                return $"{inside}|{ex.GetType().Name}:{ex.Message}";
+            }
+        }
+
+        var expected = pairs.Select(p => Observe(
+            PostVerificationGeometry.Curve.Create(p.Item1.Start, p.Item1.End,
+                ReferenceEquals(p.Item1, arc) ? arcCenter : ReferenceEquals(p.Item1, circle) ? circleCenter : null, false),
+            PostVerificationGeometry.Curve.Create(p.Item2.Start, p.Item2.End,
+                ReferenceEquals(p.Item2, arc) ? arcCenter : ReferenceEquals(p.Item2, circle) ? circleCenter : null, false))).ToArray();
+        for (var repeat = 0; repeat < 3; repeat++)
+            Assert.Equal(expected, pairs.Select(p => Observe(p.Item1, p.Item2)).ToArray());
+        Parallel.For(0, 8, _ => Assert.Equal(expected, pairs.Select(p => Observe(p.Item1, p.Item2)).ToArray()));
+        // A separate pair has not initialized either native wrapper before the readers race.
+        var coldLine = PostVerificationGeometry.Curve.Create(lineStart, lineEnd, null, false);
+        var coldCircle = PostVerificationGeometry.Curve.Create(circleStart, circleStart, circleCenter, false);
+        Parallel.For(0, 8, _ => Assert.Equal(expected[2], Observe(coldLine, coldCircle)));
+    }
+
     private static Program RoundedRectangle(double width, double height, double radius, double angle, Vector at)
     {
         var cos = System.Math.Cos(angle);

OpenNest.Tests/CuttingPlanning/NominalContourClosureTests.cs

@@ -0,0 +1,36 @@
+using OpenNest.CNC.CuttingPlanning;
+using OpenNest.Geometry;
+
+namespace OpenNest.Tests.CuttingPlanning;
+
+public class NominalContourClosureTests
+{
+    [Theory]
+    [InlineData(0.0000009, true)]
+    [InlineData(0.000001, true)]
+    [InlineData(0.00000101, false)]
+    [InlineData(0.000002, false)]
+    public void CaptureAndPreparation_AgreeAtClosureBoundary(double gap, bool accepted)
+    {
+        // Nonzero coordinates exercise roundoff at the inclusive boundary.
+        var program = new OpenNest.CNC.Program();
+        program.MoveTo(14, 3);
+        program.LineTo(24, 3);
+        program.LineTo(24, 13);
+        program.LineTo(14, 13);
+        program.LineTo(14, 3 + gap);
+        var original = OwnedProgramCopy.Copy(program);
+
+        var material = LeadMaterialSnapshot.Capture(program, new Vector(30, 20));
+
+        Assert.Equal(accepted, material.IsComplete);
+        if (accepted)
+            Assert.Equal(1, PreparedContours.Capture(program, ExplicitContourTests.Parameters()).Count);
+        else
+        {
+            Assert.Contains("closure tolerance 1E-06", material.Reason);
+            Assert.Throws<ArgumentException>(() => PreparedContours.Capture(program, ExplicitContourTests.Parameters()));
+        }
+        Assert.True(ProgramContent.Equal(original, program));
+    }
+}

OpenNest.Tests/CuttingPlanning/ReorderSearchTests.cs

@@ -34,6 +34,48 @@ public class ReorderSearchTests
         Assert.Equal(parts, plate.Parts); // Planning alone never reorders the live plate.
     }
 
+    [SkippableFact]
+    public void DenseGrid144_PerformanceProbe()
+    {
+        Skip.IfNot(Environment.GetEnvironmentVariable("OPENNEST_RUN_CUTTING_PERF") == "1",
+            "Set OPENNEST_RUN_CUTTING_PERF=1 for the 144-part cutting-planner probe.");
+        var nest = new Nest();
+        var plate = nest.CreatePlate();
+        plate.Size = new Size(100, 100);
+        foreach (var part in Grid(144, false))
+            plate.Parts.Add(part);
+        var source = plate.Parts.ToArray();
+        var timer = System.Diagnostics.Stopwatch.StartNew();
+        var result = CuttingPlanService.Plan(CuttingPlanRequest.ForPlate(plate,
+            confirmedParameters: ExplicitContourTests.Parameters(), expansionBudget: 57600));
+        timer.Stop();
+        // Expanded owned execution includes called hole programs; Program.ToString() does not,
+        // and rounds coordinates. Hash exact scalar bits in execution order instead.
+        static string Bits(double value) => BitConverter.DoubleToInt64Bits(value).ToString("X16");
+        static string Point(Vector point) => $"{Bits(point.X)},{Bits(point.Y)}";
+        var payload = string.Join("\n", result.ProposedOrder.SelectMany(p =>
+            new[] { $"part:{p.SourceOrdinal}:{Point(p.Location)}:{Bits(p.Rotation)}" }.Concat(
+                p.Execution.Motions.Select(m =>
+                {
+                    var geometry = m.Curve?.ToEntity() switch
+                    {
+                        Arc arc => $"arc:{Point(arc.Center)}:{Bits(arc.Radius)}:{Bits(arc.StartAngle)}:{Bits(arc.EndAngle)}:{arc.Rotation}",
+                        Circle circle => $"circle:{Point(circle.Center)}:{Bits(circle.Radius)}:{circle.Rotation}",
+                        Line => "line",
+                        null => "none",
+                        _ => throw new NotSupportedException("Unexpected execution curve."),
+                    };
+                    return $"{m.Layer}:{m.Rapid}:{(m.Start is { } start ? Point(start) : "null")}:{Point(m.End)}:{geometry}";
+                }))));
+        var hash = Convert.ToHexString(System.Security.Cryptography.SHA256.HashData(
+            System.Text.Encoding.UTF8.GetBytes(payload)));
+        Console.WriteLine($"Cutting144 elapsedMs={timer.Elapsed.TotalMilliseconds:F1} expansions={result.Expansions} status={result.Status} executionSha256={hash}");
+        Assert.True(result.Status == CuttingPlanStatus.Ready, Describe(result));
+        Assert.True(result.IndependentlyReplayed);
+        Assert.Equal(source.OrderBy(Key), result.ProposedOrder.Select(p => p.SourcePart).OrderBy(Key));
+        Assert.Equal(source, plate.Parts);
+    }
+
     [Fact]
     public void FreeOrder_BlockedApproach_LearnsToCutThatPartFirst()
     {

OpenNest.Tests/Data/NestDetailsSessionTests.cs

@@ -147,6 +147,74 @@ public class NestDetailsSessionTests
         await Assert.ThrowsAsync<ObjectDisposedException>(() => session.LoadAsync(Guid.NewGuid()));
     }
 
+    [Fact]
+    public async Task Prefetch_ThenLoad_ResolvesFromTheCacheWithoutASecondRequest()
+    {
+        var requested = new List<Guid>();
+        var details = new NestDetails();
+        using var session = new NestDetailsSession((id, _) =>
+        {
+            requested.Add(id);
+            return Task.FromResult(details);
+        });
+        var nestId = Guid.NewGuid();
+
+        session.Prefetch(nestId);
+        Assert.Equal(new[] { nestId }, requested);
+
+        Assert.True(await session.LoadAsync(nestId));
+        Assert.Same(details, session.Details);
+        Assert.Equal(new[] { nestId }, requested);
+    }
+
+    [Fact]
+    public async Task Prefetch_SkipsWhenAlreadyTheCurrentNest_OrAlreadyCached()
+    {
+        var requested = new List<Guid>();
+        using var session = new NestDetailsSession((id, _) =>
+        {
+            requested.Add(id);
+            return Task.FromResult(new NestDetails());
+        });
+        var nestId = Guid.NewGuid();
+
+        await session.LoadAsync(nestId);
+        Assert.Equal(new[] { nestId }, requested);
+
+        // Already the current nest.
+        session.Prefetch(nestId);
+        Assert.Equal(new[] { nestId }, requested);
+
+        // No longer current, but its earlier load is still cached.
+        session.Clear();
+        session.Prefetch(nestId);
+        Assert.Equal(new[] { nestId }, requested);
+    }
+
+    [Fact]
+    public async Task Clear_CancelsAnInFlightPrefetch_SoItsResultIsNeverCached()
+    {
+        var loads = new ControlledLoads();
+        using var session = new NestDetailsSession(loads.Load);
+        var nestId = Guid.NewGuid();
+
+        session.Prefetch(nestId);
+        Assert.False(loads.Tokens[0].IsCancellationRequested);
+
+        session.Clear();
+        Assert.True(loads.Tokens[0].IsCancellationRequested);
+        loads.Results[0].SetResult(new NestDetails());
+
+        // Whether or not the cancelled prefetch's continuation has run yet, it must not have
+        // populated the cache, so loading the same nest issues a fresh request.
+        var fresh = new NestDetails();
+        var load = session.LoadAsync(nestId);
+        Assert.Equal(2, loads.Results.Count);
+        loads.Results[1].SetResult(fresh);
+        Assert.True(await load);
+        Assert.Same(fresh, session.Details);
+    }
+
     /// <summary>Each load waits for its own result, which the test completes explicitly.</summary>
     private sealed class ControlledLoads
     {

OpenNest.Tests/Data/NestStorageTests.cs

@@ -59,6 +59,31 @@ public class NestStorageSettingsTests : IDisposable
         Assert.False(settings.IsDatabaseMode);
     }
 
+    [Fact]
+    public void TryNormalizeServerUrl_AcceptsHttpsWithoutChangingMode()
+    {
+        var settings = new NestStorageSettings { Mode = NestStorageMode.File };
+
+        Assert.True(NestStorageSettings.TryNormalizeServerUrl(" https://shop.example:8090/ ", out var url));
+        settings.ServerUrl = url;
+        settings.Save(FilePath);
+
+        var loaded = NestStorageSettings.Load(FilePath);
+        Assert.Equal("https://shop.example:8090", loaded.ServerUrl);
+        Assert.Equal(NestStorageMode.File, loaded.Mode);
+        Assert.False(loaded.IsDatabaseMode);
+    }
+
+    [Theory]
+    [InlineData("")]
+    [InlineData("ftp://shop.example")]
+    [InlineData("not-a-url")]
+    public void TryNormalizeServerUrl_RejectsInvalidAddress(string input)
+    {
+        Assert.False(NestStorageSettings.TryNormalizeServerUrl(input, out var url));
+        Assert.Equal("", url);
+    }
+
     public void Dispose()
     {
         if (Directory.Exists(_directory))

OpenNest.Tests/Diagnostics/PostVerificationAnalyzerTests.cs

@@ -36,6 +36,9 @@ public class PostVerificationAnalyzerTests
         var report = Analyze(Cutoff(30, 30), a, Scribe(40, 40), b);
         var overlap = Assert.Single(Find(report, PostVerificationKind.Overlap));
         Assert.Equal((1, 2, 4), (overlap.PlateNumber, overlap.PartNumber, overlap.OtherPartNumber));
+        Assert.NotNull(overlap.Overlap);
+        Assert.Equal(new Vector(1.5, 1.5), overlap.Location);
+        Assert.Equal(1, overlap.Overlap.Area, 6);
         Assert.True(report.HasWarnings);
         Assert.False(report.CanPost(false));
         Assert.True(report.CanPost(true));
@@ -58,7 +61,8 @@ public class PostVerificationAnalyzerTests
     {
         var part = Rectangle(0, 0, 4);
         part.HasManualLeadIns = true;
-        Assert.Single(Find(Analyze(part), PostVerificationKind.MissingLeadIn));
+        var finding = Assert.Single(Find(Analyze(part), PostVerificationKind.MissingLeadIn));
+        Assert.Equal(Vector.Zero, finding.Location);
     }
 
     [Fact]
@@ -105,8 +109,12 @@ public class PostVerificationAnalyzerTests
     public void Rapid_ThroughPreviouslyCutPartWarns()
     {
         var report = Analyze(Rectangle(0, 0, 4), Scribe(-2, 2), Scribe(6, 2));
-        Assert.Contains(Find(report, PostVerificationKind.RapidCrossing), f =>
+        var crossing = Assert.Single(Find(report, PostVerificationKind.RapidCrossing).Where(f =>
-            f.PartNumber == 3 && f.OtherPartNumber == 1);
+            f.PartNumber == 3 && f.OtherPartNumber == 1));
+        Assert.NotNull(crossing.RapidStart);
+        Assert.NotNull(crossing.RapidEnd);
+        Assert.Equal(new[] { new Vector(0, 2), new Vector(4, 2) }, crossing.ContactPoints);
+        Assert.Equal((crossing.RapidStart.Value + crossing.RapidEnd.Value) * 0.5, crossing.Location);
     }
 
     [Fact]
@@ -169,8 +177,11 @@ public class PostVerificationAnalyzerTests
     public void Rapid_CutoffTravelStillCrossesEarlierRealCuts()
     {
         var report = Analyze(Rectangle(0, 0, 4), Scribe(-2, 2), Cutoff(6, 2));
-        Assert.Contains(Find(report, PostVerificationKind.RapidCrossing), f =>
+        var crossing = Assert.Single(Find(report, PostVerificationKind.RapidCrossing).Where(f =>
-            f.PartNumber == 3 && f.OtherPartNumber == 1);
+            f.PartNumber == 3 && f.OtherPartNumber == 1));
+        Assert.NotNull(crossing.RapidStart);
+        Assert.NotNull(crossing.RapidEnd);
+        Assert.Equal((crossing.RapidStart.Value + crossing.RapidEnd.Value) * 0.5, crossing.Location);
     }
 
     [Theory]

OpenNest.Tests/Diagnostics/RapidContactPointTests.cs

@@ -0,0 +1,52 @@
+using OpenNest.Diagnostics;
+using OpenNest.Geometry;
+
+namespace OpenNest.Tests.Diagnostics;
+
+public class RapidContactPointTests
+{
+    [Theory]
+    [InlineData(-2, 2, 6, 2, 2)]
+    [InlineData(-2, -2, 6, 6, 2)] // Shared corners are deduplicated.
+    [InlineData(-2, 4, 6, 4, 2)] // Collinear contact span.
+    [InlineData(-2, 2, 0, 2, 1)] // Endpoint arrival.
+    [InlineData(0, 0, -2, -2, 0)] // Start-only departure.
+    [InlineData(1, 1, 2, 2, 0)] // Entirely inside.
+    public void RectangleContacts(double x1, double y1, double x2, double y2, int count)
+    {
+        var vertices = new[] { new Vector(0, 0), new Vector(4, 0), new Vector(4, 4), new Vector(0, 4) };
+        var curves = Enumerable.Range(0, 4).Select(i =>
+            PostVerificationGeometry.Curve.Create(vertices[i], vertices[(i + 1) % 4], null, false)).ToArray();
+        var start = new Vector(x1, y1);
+        var end = new Vector(x2, y2);
+        var points = PostVerificationGeometry.ContactPoints(start, end, curves, default);
+        Assert.Equal(count, points.Count);
+        Assert.True(((ICollection<Vector>)points).IsReadOnly);
+        Assert.All(points, point =>
+        {
+            Assert.Contains(curves, curve => curve.Contains(point));
+            Assert.True(new Line(start, end).ClosestPointTo(point).DistanceTo(point) < 1e-8);
+        });
+        Assert.Equal(points.OrderBy(point => point.DistanceTo(start)), points);
+    }
+
+    [Theory]
+    [InlineData(0, 2)]
+    [InlineData(1, 1)] // Tangency has a single marker.
+    public void CircleContactsUseNativeCurve(double y, int count)
+    {
+        var circle = PostVerificationGeometry.Curve.Create(new Vector(1, 0), new Vector(1, 0), Vector.Zero, false);
+        var points = PostVerificationGeometry.ContactPoints(new Vector(-2, y), new Vector(2, y), [circle], default);
+        Assert.Equal(count, points.Count);
+        Assert.All(points, point => Assert.Equal(1, point.DistanceTo(Vector.Zero), 8));
+        Assert.Equal(new Vector(count == 1 ? 0 : -1, y), points[0]);
+    }
+
+    [Fact]
+    public void ArcContactsExcludeUnusedCircleHalf()
+    {
+        var arc = PostVerificationGeometry.Curve.Create(new Vector(0, -1), new Vector(0, 1), Vector.Zero, false);
+        var points = PostVerificationGeometry.ContactPoints(new Vector(-2, 0), new Vector(2, 0), [arc], default);
+        Assert.Equal(new Vector(1, 0), Assert.Single(points));
+    }
+}

OpenNest.Tests/Engine/CutoutPipelinePersistenceTests.cs

@@ -0,0 +1,73 @@
+using OpenNest.CNC;
+using OpenNest.Engine;
+using OpenNest.Engine.Jobs;
+using OpenNest.Geometry;
+using OpenNest.IO;
+
+namespace OpenNest.Tests.Engine;
+
+public class CutoutPipelinePersistenceTests
+{
+    [Fact]
+    public void ExpandedMultiSheetProposalCommitsAndReloadsAsSeparateDrawings()
+    {
+        var frame = new OpenNest.Shapes.RingShape { OuterDiameter = 20, InnerDiameter = 10 }
+            .GetDrawing();
+        frame.Name = "neutral-frame";
+        var program = new Program();
+        program.MoveTo(0, 0);
+        program.LineTo(6, 0);
+        program.LineTo(6, 6);
+        program.LineTo(0, 6);
+        program.LineTo(0, 0);
+        var insert = new Drawing("neutral-insert", program);
+        var request = new NestPipelineRequest("Irregular", new[] {
+            new NestItem { Drawing = frame, Quantity = 2 },
+            new NestItem { Drawing = insert, Quantity = 2 } },
+            new[] { new NestPlateStock("sheet", new Size(22, 22), 2, 0.25) },
+            new NestJobOptions(maxPlates: 2));
+        var ordinary = NestPipeline.Run(request);
+        Assert.Contains(ordinary.Raw.Fulfillment, f => f.Unplaced > 0);
+        var result = NestPipeline.RunCutoutPreview(request);
+        Assert.True(result.IsValid, string.Join("; ", result.Violations));
+        Assert.Equal(2, result.Raw.Plates.Count);
+        Assert.All(result.Raw.Plates, p => Assert.Equal(new[] { "part-0", "part-1" },
+            p.Placements.Select(x => x.PartId)));
+
+        var nest = new Nest();
+        nest.Drawings.Add(frame);
+        nest.Drawings.Add(insert);
+        using (var manager = new PlateManager(nest))
+        {
+            var committed = NestPipelineCommit.ApplyToEmptyPlates(result, manager);
+            Assert.Equal(2, committed.Count);
+            Assert.All(committed, plate => Assert.Equal(new[] { frame, insert },
+                plate.Parts.Select(p => p.BaseDrawing)));
+        }
+        Assert.Equal(2, frame.Quantity.Nested);
+        Assert.Equal(2, insert.Quantity.Nested);
+        using var stream = new MemoryStream();
+        Assert.True(new NestWriter(nest).Write(stream));
+        var loaded = new NestReader(new MemoryStream(stream.ToArray())).Read();
+        Assert.Equal(2, loaded.Plates.Count);
+        for (var i = 0; i < loaded.Plates.Count; i++)
+        {
+            var expected = nest.Plates[i];
+            var actual = loaded.Plates[i];
+            Assert.Equal(expected.Size, actual.Size);
+            Assert.Equal(expected.PartSpacing, actual.PartSpacing);
+            Assert.Equal(expected.Quadrant, actual.Quadrant);
+            Assert.Equal(expected.EdgeSpacing, actual.EdgeSpacing);
+            Assert.Equal(new[] { "neutral-frame", "neutral-insert" },
+                actual.Parts.Select(p => p.BaseDrawing.Name));
+            for (var j = 0; j < actual.Parts.Count; j++)
+            {
+                Assert.Equal(expected.Parts[j].Location.X, actual.Parts[j].Location.X, 6);
+                Assert.Equal(expected.Parts[j].Location.Y, actual.Parts[j].Location.Y, 6);
+                Assert.Equal(expected.Parts[j].Rotation, actual.Parts[j].Rotation, 6);
+            }
+        }
+        Assert.Equal(2, loaded.Drawings.Single(d => d.Name == "neutral-frame").Quantity.Nested);
+        Assert.Equal(2, loaded.Drawings.Single(d => d.Name == "neutral-insert").Quantity.Nested);
+    }
+}

OpenNest.Tests/Fill/CompactorTests.cs

@@ -527,6 +527,72 @@ namespace OpenNest.Tests.Fill
             Assert.True(part.BoundingBox.Bottom < 1);
         }
 
+        [Fact]
+        public void SettlePlacement_RepeatsAfterVerticalMovementOpensHorizontalPath()
+        {
+            var plate = new Plate(100, 100);
+            plate.Parts.Add(MakeRectPart(20, 20, 20, 30));
+            var moving = MakeRectPart(60, 35, 10, 10);
+
+            Compactor.SettlePlacement(new List<Part> { moving }, plate,
+                PushDirection.Left, PushDirection.Down);
+
+            Assert.Equal(0, moving.BoundingBox.Left, 6);
+            Assert.Equal(0, moving.BoundingBox.Bottom, 6);
+            Assert.False(moving.Intersects(plate.Parts[0], out _));
+        }
+
+        [Fact]
+        public void SettlePlacement_MovesCopiedGroupTogether()
+        {
+            var plate = new Plate(100, 100);
+            var left = MakeRectPart(40, 40, 5, 5);
+            var right = MakeRectPart(50, 40, 5, 5);
+            var originalGap = right.Location.X - left.Location.X;
+
+            Compactor.SettlePlacement(new List<Part> { left, right }, plate,
+                PushDirection.Left, PushDirection.Down);
+
+            Assert.Equal(0, left.BoundingBox.Left, 6);
+            Assert.Equal(0, left.BoundingBox.Bottom, 6);
+            Assert.Equal(originalGap, right.Location.X - left.Location.X, 6);
+        }
+
+        [Fact]
+        public void SettlePlacement_GeometryRepeatsWhenInitialBoxPassIsSkipped()
+        {
+            var plate = new Plate(100, 100);
+            plate.Parts.Add(MakeRectPart(20, 20, 20, 30));
+            // Its bounding box covers the start, but its material is above it.
+            plate.Parts.Add(MakeTrianglePart(new Vector(0, 100),
+                new Vector(100, 100), new Vector(100, 40)));
+            var moving = MakeRectPart(60, 35, 10, 10);
+
+            Compactor.SettlePlacement(new List<Part> { moving }, plate,
+                PushDirection.Left, PushDirection.Down);
+
+            Assert.Equal(0, moving.BoundingBox.Left, 6);
+            Assert.Equal(0, moving.BoundingBox.Bottom, 6);
+            Assert.All(plate.Parts, obstacle => Assert.False(moving.Intersects(obstacle, out _)));
+        }
+
+        [Fact]
+        public void SettlePlacement_SkipsBoxPassWhenAlreadyInsideObstacleBounds()
+        {
+            // Triangle material sits below the diagonal; the free pocket at (25,25)
+            // is within its bounding box. A box-only slide would falsely block it.
+            var plate = new Plate(100, 100);
+            plate.Parts.Add(MakeTrianglePart(new Vector(0, 0),
+                new Vector(40, 0), new Vector(0, 40)));
+            var moving = MakeRectPart(25, 25, 5, 5);
+            var start = moving.Location;
+
+            Compactor.SettlePlacement(new List<Part> { moving }, plate,
+                PushDirection.Left, PushDirection.Down, maxIterations: 0);
+
+            Assert.Equal(start, moving.Location);
+        }
+
         [Fact]
         public void PushBoundingBox_Left_MovesPartTowardEdge()
         {

OpenNest.Tests/PartColorPaletteTests.cs

@@ -0,0 +1,49 @@
+using System.Drawing;
+
+namespace OpenNest.Tests;
+
+public class PartColorPaletteTests
+{
+    [Theory]
+    [InlineData(0, 216, 49, 49)]
+    [InlineData(1, 98, 160, 234)]
+    [InlineData(2, 253, 150, 167)]
+    [InlineData(3, 157, 211, 226)]
+    public void GoldenAngleMatchesWideRangeHslSamples(int index, int r, int g, int b)
+        => Assert.Equal(Color.FromArgb(r, g, b), PartColorPalette.GoldenAngle(index));
+
+    [Fact]
+    public void GoldenAngleContinuesPastPaletteLengthAndStaysOutOfEtchBand()
+    {
+        var colors = Enumerable.Range(0, 1000).Select(PartColorPalette.GoldenAngle).ToArray();
+        Assert.NotEqual(colors[0], colors[12]);
+        Assert.All(colors, color =>
+        {
+            Assert.Equal(255, color.A);
+            // The green band belongs to etch strokes; no generated fill may land in it.
+            var hue = color.GetHue();
+            Assert.True(hue < 95 || hue >= 165, $"Fill hue {hue:F0} collides with the etch-green band.");
+        });
+        Assert.Equal(colors, Enumerable.Range(0, 1000).Select(PartColorPalette.GoldenAngle));
+        Assert.InRange(PartColorPalette.GoldenAngle(int.MaxValue).GetBrightness(), 0.4f, 0.85f);
+    }
+
+    [Fact]
+    public void NeighboringPartsStayFarApartInRgb()
+    {
+        static double Distance(Color a, Color b) =>
+            System.Math.Sqrt((a.R - b.R) * (double)(a.R - b.R)
+                + (a.G - b.G) * (a.G - b.G)
+                + (a.B - b.B) * (a.B - b.B));
+
+        var colors = Enumerable.Range(0, 48).Select(PartColorPalette.GoldenAngle).ToArray();
+        Assert.Equal(48, colors.Select(c => c.ToArgb()).Distinct().Count());
+        for (var i = 0; i < colors.Length - 1; i++)
+            Assert.True(Distance(colors[i], colors[i + 1]) >= 90,
+                $"Parts {i} and {i + 1} are too similar: {Distance(colors[i], colors[i + 1]):F0}.");
+    }
+
+    [Fact]
+    public void GoldenAngleRejectsNegativeIndices()
+        => Assert.Throws<ArgumentOutOfRangeException>(() => PartColorPalette.GoldenAngle(-1));
+}

OpenNest.Tests/Reporting/NestPdfLayoutTests.cs

@@ -32,12 +32,12 @@ public sealed class NestPdfLayoutTests : IDisposable
         var summary = pages[0];
         Assert.Matches(@"Distinct layouts:\s+4", summary);
         Assert.Matches(@"Total physical sheets:\s+7", summary);
-        // Bracket R001: 2/sheet x 2 + 1 x 3 + 1 x 1 = 8. Same-named R003: 1 x 2 + 1 x 1 = 3.
+        // Bracket 1: 2/sheet x 2 + 1 x 3 + 1 x 1 = 8. Same-named 3: 1 x 2 + 1 x 1 = 3.
-        Assert.Matches(@"R001\s+Bracket\s+5\s+8\s+0\s+3\s+1-2, 4", summary);
+        Assert.Matches(@"1\s+Bracket\s+5\s+8\s+0\s+3\s+1-2, 4", summary);
-        Assert.Matches(@"R002\s+Rotated\s+1\s+3\s+0\s+2\s+1, 3", summary);
+        Assert.Matches(@"2\s+Rotated\s+1\s+3\s+0\s+2\s+1, 3", summary);
-        Assert.Matches(@"R003\s+Bracket\s+7\s+3\s+4\s+0\s+1, 3", summary);
+        Assert.Matches(@"3\s+Bracket\s+7\s+3\s+4\s+0\s+1, 3", summary);
-        Assert.Matches(@"R004\s+Unplaced\s+3\s+0\s+3\s+0\s+-", summary);
+        Assert.Matches(@"4\s+Unplaced\s+3\s+0\s+3\s+0\s+-", summary);
-        Assert.Matches(@"3\s+60 x 30 in\s+1\s+2", summary);
+        Assert.Matches(@"3\s+30 x 60 in\s+1\s+2", summary);
         for (var plate = 1; plate <= 4; plate++)
         {
             var page = pages[plate];
@@ -45,10 +45,10 @@ public sealed class NestPdfLayoutTests : IDisposable
             Assert.Contains($"Page {plate + 1} of 5", page);
             Assert.Contains("Nest report: Report test job", page);
         }
-        Assert.Matches(@"R001\s+Bracket\s+1\s+3", pages[2]);
+        Assert.Matches(@"1\s+Bracket\s+1\s+3", pages[2]);
-        Assert.Matches(@"R002\s+Rotated\s+1\s+1", pages[3]);
+        Assert.Matches(@"2\s+Rotated\s+1\s+1", pages[3]);
-        Assert.Matches(@"R003\s+Bracket\s+1\s+1", pages[3]);
+        Assert.Matches(@"3\s+Bracket\s+1\s+1", pages[3]);
-        Assert.DoesNotContain("R001", pages[3]);
+        Assert.DoesNotMatch(@"(?m)^1\s+Bracket", pages[3]);
     }
 
     [SkippableFact]
@@ -72,23 +72,23 @@ public sealed class NestPdfLayoutTests : IDisposable
         var summaryText = string.Join("\n", summaryPages);
         // Every row exactly once; the Parts heading row repeats on every continuation page.
         for (var id = 1; id <= 74; id++)
-            Assert.Single(Regex.Matches(summaryText, $@"(?m)^\s*R{id:D3}\s"));
+            Assert.Single(Regex.Matches(summaryText, $@"(?m)^\s*{id}\s+(?:Bracket|Rotated|Unplaced|Demand)\b"));
         Assert.All(summaryPages.Skip(1), page => Assert.Matches(@"ID\s+Part\s+Drawing\s+Required\s+Nested\s+Shortage", page));
-        // Placements first (R004-R043 on plate 1), then unplaced demand by ordinal name.
+        // Placements first (4-43 on plate 1), then unplaced demand by ordinal name.
-        Assert.Matches(@"R043\s+Demand 39\s+40\s+2\s+38\s+0\s+1", summaryText);
+        Assert.Matches(@"43\s+Demand 39\s+40\s+2\s+38\s+0\s+1", summaryText);
-        Assert.Matches(@"R073\s+Demand 69\s+70\s+0\s+70\s+0\s+-", summaryText);
+        Assert.Matches(@"73\s+Demand 69\s+70\s+0\s+70\s+0\s+-", summaryText);
-        Assert.Matches(@"R074\s+Unplaced\s+3\s+0\s+3\s+0\s+-", summaryText);
+        Assert.Matches(@"74\s+Unplaced\s+3\s+0\s+3\s+0\s+-", summaryText);
 
         var platePages = pages.Where(page => page.Contains("Plate 1 of 4")).ToList();
         Assert.True(platePages.Count >= 2, $"plate 1 pages: {platePages.Count}");
         Assert.All(platePages, page => Assert.Contains("Nest report: Report test job", page));
         // Every page carrying plate-table rows repeats the table heading.
-        var tablePages = platePages.Where(page => Regex.IsMatch(page, @"(?m)^R\d{3}\s+Demand \d{2}\s+1\s+2$")).ToList();
+        var tablePages = platePages.Where(page => Regex.IsMatch(page, @"(?m)^\d+\s+Demand \d{2}\s+1\s+2$")).ToList();
         Assert.True(tablePages.Count >= 2, $"plate table pages: {tablePages.Count}");
-        Assert.All(tablePages, page => Assert.Matches(@"ID\s+Drawing\s+Qty/sheet\s+Total \(2 copies\)", page));
+        Assert.All(tablePages, page => Assert.Matches(@"ID\s+Drawing\s+Parts per plate\s+Total \(2 plates\)", page));
         var plateText = string.Join("\n", platePages);
         for (var i = 0; i < 40; i++)
-            Assert.Matches($@"R{i + 4:D3}\s+Demand {i:D2}\s+1\s+2", plateText);
+            Assert.Matches($@"{i + 4}\s+Demand {i:D2}\s+1\s+2", plateText);
         Assert.DoesNotContain("Demand 40", plateText);
         for (var page = 1; page <= total; page++)
             Assert.Contains($"Page {page} of {total}", pages[page - 1]);
@@ -110,11 +110,11 @@ public sealed class NestPdfLayoutTests : IDisposable
         Assert.Equal(Enumerable.Range(0, 900), notes);
         Assert.Contains(string.Concat(Enumerable.Repeat("X", 120)), Regex.Replace(all, @"\s+", ""));
         // The long drawing name is wrapped inside its column on the summary and plate tables.
-        var summaryPage = Array.FindIndex(pages, page => page.Contains("Required") && page.Contains("R002"));
+        var summaryPage = Array.FindIndex(pages, page => page.Contains("Required") && page.Contains("2"));
         var platePage = Array.FindIndex(pages, page => page.Contains("Plate 1 of 4"));
         Assert.True(summaryPage >= 0 && platePage > summaryPage);
         Assert.Equal(longName.Replace(" ", ""), ColumnText(path, summaryPage + 1, "Drawing", "Required"));
-        Assert.Equal(longName.Replace(" ", ""), ColumnText(path, platePage + 1, "Drawing", "Qty/sheet"));
+        Assert.Equal(longName.Replace(" ", ""), ColumnText(path, platePage + 1, "Drawing", "Parts"));
         // Column headings stay on one line.
         Assert.Matches(@"ID\s+Part\s+Drawing\s+Required\s+Nested\s+Shortage\s+Extra\s+Plates", pages[summaryPage]);
     }
@@ -143,7 +143,7 @@ public sealed class NestPdfLayoutTests : IDisposable
         Assert.Equal(5, pages.Length);
         Assert.Contains("millimeters (mm)", pages[0]);
         Assert.Contains("3 mm", pages[0]);
-        Assert.Matches(@"48 x 24 mm", pages[2]);
+        Assert.Matches(@"24 x 48 mm", pages[2]);
         using var pdf = PdfReader.Open(path, PdfDocumentOpenMode.Import);
         var stream = ReportPdf.ContentStreams(pdf.Pages[1]).Last();
         stream = stream[(stream.IndexOf("W* n", StringComparison.Ordinal) + 4)..];
@@ -164,56 +164,73 @@ public sealed class NestPdfLayoutTests : IDisposable
     }
 
     [SkippableFact]
-    public void Write_TinyRepeatedPartsGetMapGridDetailViewsWithEveryIdLegible()
+    public void Write_TinyRepeatedPartsShareOneDottedGroupOnThePlatePage()
     {
         var nest = NestReportTestData.CreateDenseNest();
         var snapshot = NestReportBuilder.Capture(nest, NestReportTestData.GeneratedAt);
-        var plan = NestReportDiagram.Plan(snapshot.Plates[0], 720, 320, 400);
+        var plan = NestReportDiagram.Plan(snapshot.Plates[0], 720, 320);
-        Assert.NotNull(plan.Overview.Grid);
+        var group = Assert.Single(plan.Groups);
-        Assert.NotEmpty(plan.Details);
+        Assert.Equal("2", group.Label.Id);
-        // Every placement is labeled at full size somewhere; none are dropped.
+        Assert.Equal(Enumerable.Range(2, 24), group.Parts.Order());
-        var labeled = plan.Overview.Labels.Select(label => label.Part)
+        Assert.Equal(2, plan.Labels.Count);
-            .Concat(plan.Details.SelectMany(detail => detail.Labels.Select(label => label.Part))).ToHashSet();
+        Assert.DoesNotContain(plan.Labels, label => label.Id == "2");
-        Assert.Equal(Enumerable.Range(0, snapshot.Plates[0].Parts.Length), labeled.Order());
+        Assert.All(group.Parts, index => Assert.True(group.Boundary.Contains(plan.Fit.Rect(snapshot.Plates[0].Parts[index].Geometry.Bounds))));
+        Assert.False(group.Boundary.IntersectsWith(group.Label.Box));
+        var labels = plan.Labels.Append(group.Label).ToList();
         var font = NestReportDiagram.LabelFont();
-        Assert.Equal(NestReportDiagram.LabelFontSize, font.Size);
+        foreach (var label in labels)
-        foreach (var view in plan.Details.Prepend(plan.Overview))
-        {
-            foreach (var label in view.Labels)
         {
             Assert.True(label.Box.Width >= ReportText.Size(label.Id, font).Width);
-                Assert.True(label.Box.X >= 0 && label.Box.Right <= view.Size.Width && label.Box.Y >= 0 && label.Box.Bottom <= view.Size.Height);
+            Assert.True(new PdfSharp.Drawing.XRect(0, 0, 720, 320).Contains(label.Box));
-                Assert.DoesNotContain(view.Labels, other => other != label && other.Box.IntersectsWith(label.Box));
+            Assert.DoesNotContain(labels, other => other != label && other.Box.IntersectsWith(label.Box));
-                // Labels sit on material, not in the washer hole.
-                var center = view.Fit.Model(new PdfSharp.Drawing.XPoint(label.Box.X + label.Box.Width / 2, label.Box.Y + label.Box.Height / 2));
-                var part = snapshot.Plates[0].Parts[label.Part].Geometry;
-                var hole = part.Contours.SelectMany(contour => contour.Segments).Single(segment => segment.Center != null);
-                var dx = center.X - hole.Center!.X;
-                var dy = center.Y - hole.Center.Y;
-                Assert.True(dx * dx + dy * dy > hole.Radius * hole.Radius, $"{label.Id} label is inside its hole");
         }
-        }
-
         var path = Write(nest);
         var pages = ReportPdf.Pages(path);
-        var plateText = string.Join("\n", pages.Skip(1));
+        Assert.Equal(2, pages.Length);
-        Assert.Contains("cells outlined dash-dot have detail views", plateText);
+        Assert.Contains("A dotted outline groups like parts under one ID", pages[1]);
-        foreach (var detail in plan.Details)
+        Assert.DoesNotContain("detail", pages[1]);
-            Assert.Contains($"Plate 1 detail {detail.Cell}:", plateText);
+        using var pdf = PdfReader.Open(path, PdfDocumentOpenMode.Import);
-        var washerLabels = pages.Skip(1).Sum(page => Regex.Matches(page, @"\bR002\b").Count);
+        var diagram = ReportPdf.ContentStreams(pdf.Pages[1]).Last();
-        // 24 diagram labels plus one table row.
+        Assert.Matches(@"\[0\.6 1\.8\]\s*0\s+d", diagram);
-        Assert.True(washerLabels >= 25, $"R002 occurrences: {washerLabels}");
+    }
+
+    [Theory]
+    [InlineData(false)]
+    [InlineData(true)]
+    public void Plan_GroupDoesNotEncloseUnrelatedPartsOrCutoffs(bool cutoff)
+    {
+        var nest = NestReportTestData.CreateDenseNest();
+        var drawing = NestReportTestData.Rectangle("Obstacle", 0.1, 0.1);
+        drawing.IsCutOff = cutoff;
+        nest.Plates[0].Parts.Add(new Part(drawing, new Vector(63.2, 31.2)));
+        var snapshot = NestReportBuilder.Capture(nest, NestReportTestData.GeneratedAt);
+        var plan = NestReportDiagram.Plan(snapshot.Plates[0], 720, 320);
+        Assert.Empty(plan.Groups);
+        Assert.Equal(2, plan.Labels.Count);
+    }
+
+    [Fact]
+    public void Plan_SeparatedClustersOfTheSamePartGetSeparateGroups()
+    {
+        var nest = NestReportTestData.CreateDenseNest();
+        var plate = nest.Plates[0];
+        for (var i = 14; i < 26; i++)
+            plate.Parts[i].Offset(25, 0);
+        var snapshot = NestReportBuilder.Capture(nest, NestReportTestData.GeneratedAt);
+        var plan = NestReportDiagram.Plan(snapshot.Plates[0], 720, 320);
+        Assert.Equal(2, plan.Groups.Count);
+        Assert.All(plan.Groups, group => Assert.Equal(12, group.Parts.Count));
+        Assert.False(plan.Groups[0].Boundary.IntersectsWith(plan.Groups[1].Boundary));
     }
 
     [SkippableFact]
     public void Write_LabelOnHoledPartAvoidsTheHole()
     {
         var snapshot = NestReportBuilder.Capture(NestReportTestData.CreateNest(), NestReportTestData.GeneratedAt);
-        var plan = NestReportDiagram.Plan(snapshot.Plates[0], 720, 320, 400);
+        var plan = NestReportDiagram.Plan(snapshot.Plates[0], 720, 320);
-        Assert.Empty(plan.Details);
+        var label = plan.Labels.First(label => label.Part == 0);
-        var label = plan.Overview.Labels.First(label => label.Part == 0);
         var hole = snapshot.Plates[0].Parts[0].Geometry.Contours.SelectMany(c => c.Segments).Single(s => s.Center != null);
-        var holeBox = plan.Overview.Fit.Rect(new ReportBounds(hole.Center!.X - hole.Radius, hole.Center.Y - hole.Radius,
+        var holeBox = plan.Fit.Rect(new ReportBounds(hole.Center!.X - hole.Radius, hole.Center.Y - hole.Radius,
             hole.Center.X + hole.Radius, hole.Center.Y + hole.Radius));
         Assert.False(label.Box.IntersectsWith(holeBox));
     }
@@ -235,10 +252,9 @@ public sealed class NestPdfLayoutTests : IDisposable
         nest.Plates.Add(plate);
         var snapshot = NestReportBuilder.Capture(nest, NestReportTestData.GeneratedAt);
 
-        var plan = NestReportDiagram.Plan(snapshot.Plates[0], 720, 320, 400);
+        var plan = NestReportDiagram.Plan(snapshot.Plates[0], 720, 320);
 
-        Assert.Empty(plan.Details);
+        foreach (var label in plan.Labels)
-        foreach (var label in plan.Overview.Labels)
         {
             var geometry = snapshot.Plates[0].Parts[label.Part].Geometry;
             var origin = new Vector(geometry.Bounds.Left, geometry.Bounds.Bottom);
@@ -248,14 +264,14 @@ public sealed class NestPdfLayoutTests : IDisposable
             foreach (var ring in rings)
                 ring.Offset(-origin.X, -origin.Y);
             var pole = PolyLabel.Find(rings[0], rings.Skip(1).ToList(), NestReportDiagram.PolePrecision(geometry.Bounds));
-            var expected = plan.Overview.Fit.Point(pole.X + origin.X, pole.Y + origin.Y);
+            var expected = plan.Fit.Point(pole.X + origin.X, pole.Y + origin.Y);
             // Pole of the placement-independent copy, to within the search precision.
-            var tolerance = NestReportDiagram.PolePrecision(geometry.Bounds) * plan.Overview.Fit.Scale;
+            var tolerance = NestReportDiagram.PolePrecision(geometry.Bounds) * plan.Fit.Scale;
             Assert.InRange(label.Box.X + label.Box.Width / 2 - expected.X, -tolerance, tolerance);
             Assert.InRange(label.Box.Y + label.Box.Height / 2 - expected.Y, -tolerance, tolerance);
         }
-        var l = plan.Overview.Labels.Single(label => label.Part == 0);
+        var l = plan.Labels.Single(label => label.Part == 0);
-        var center = plan.Overview.Fit.Model(new PdfSharp.Drawing.XPoint(l.Box.X + l.Box.Width / 2, l.Box.Y + l.Box.Height / 2));
+        var center = plan.Fit.Model(new PdfSharp.Drawing.XPoint(l.Box.X + l.Box.Width / 2, l.Box.Y + l.Box.Height / 2));
         // The pole of this L is in its corner square, about 1.17 in from both outer edges.
         Assert.InRange(center.X - 4, 0.9, 1.4);
         Assert.InRange(center.Y - 4, 0.9, 1.4);
@@ -266,14 +282,12 @@ public sealed class NestPdfLayoutTests : IDisposable
     {
         // A square with a central hole has four equally deep poles; every copy must pick the same one.
         var snapshot = NestReportBuilder.Capture(NestReportTestData.CreateDenseNest(), NestReportTestData.GeneratedAt);
-        var plan = NestReportDiagram.Plan(snapshot.Plates[0], 720, 320, 400);
+        var plan = NestReportDiagram.Plan(snapshot.Plates[0], 720, 320);
-        foreach (var view in plan.Details.Prepend(plan.Overview))
+        var offsets = plan.Labels.GroupBy(label => label.Id).SelectMany(group =>
-        {
-            var offsets = view.Labels.GroupBy(label => label.Id).SelectMany(group =>
         {
             var relative = group.Select(label =>
             {
-                    var bounds = view.Fit.Rect(snapshot.Plates[0].Parts[label.Part].Geometry.Bounds);
+                var bounds = plan.Fit.Rect(snapshot.Plates[0].Parts[label.Part].Geometry.Bounds);
                 return (X: label.Box.X - bounds.X, Y: label.Box.Y - bounds.Y);
             }).ToList();
             return relative.Select(offset => (offset.X - relative[0].X, offset.Y - relative[0].Y));
@@ -283,8 +297,7 @@ public sealed class NestPdfLayoutTests : IDisposable
             Assert.InRange(delta.Item1, -0.01, 0.01);
             Assert.InRange(delta.Item2, -0.01, 0.01);
         });
-        }
+        Assert.Equal(2, plan.Labels.Count(label => label.Id == "1"));
-        Assert.Equal(24, plan.Details.Sum(detail => detail.Labels.Count(label => label.Id == "R002")));
     }
 
     private static OpenNest.Geometry.Shape ToShape(ReportContour contour)
@@ -401,14 +414,14 @@ public sealed class NestPdfLayoutTests : IDisposable
         Assert.Contains("second  line", lines);
     }
 
-    /// <summary>Text of the R002 row inside one table column, read from word boxes in reading order.</summary>
+    /// <summary>Text of the 2 row inside one table column, read from word boxes in reading order.</summary>
     private static string ColumnText(string path, int page, string column, string next)
     {
         var words = ReportPdf.Words(path, page);
         var heading = words.First(word => word.Text == column);
         var limit = words.First(word => word.Text == next && System.Math.Abs(word.Top - heading.Top) < 1);
-        var above = words.First(word => word.Text == "R001" && word.Top > heading.Top);
+        var above = words.First(word => word.Text == "1" && word.Left < heading.Left && word.Top > heading.Top);
-        var below = words.First(word => word.Text == "R003" && word.Top > above.Top);
+        var below = words.First(word => word.Text == "3" && word.Left < heading.Left && word.Top > above.Top);
         var cell = words.Where(word => word.Left >= heading.Left - 1 && word.Right <= limit.Left
                 && word.Top > above.Bottom && word.Bottom < below.Top)
             .OrderBy(word => word.Top).ThenBy(word => word.Left);

OpenNest.Tests/Reporting/NestPdfWriterTests.cs

@@ -47,20 +47,24 @@ public sealed class NestPdfWriterTests : IDisposable
         Assert.Contains("2026-09-29 12:00 +00:00", summary);
         Assert.Matches(@"Distinct layouts:\s+1", summary);
         Assert.Matches(@"Total physical sheets:\s+2", summary);
-        Assert.Matches(@"1\s+48 x 24 in\s+2\s+4\s+\d+\.\d%", summary);
+        Assert.Matches(@"1\s+24 x 48 in\s+2\s+4\s+\d+\.\d%", summary);
-        Assert.Matches(@"R001\s+Bracket\s+5\s+4\s+1\s+0\s+1", summary);
+        Assert.Matches(@"1\s+Bracket\s+5\s+4\s+1\s+0\s+1", summary);
-        Assert.Matches(@"R002\s+Rotated\s+1\s+2\s+0\s+1\s+1", summary);
+        Assert.Matches(@"2\s+Rotated\s+1\s+2\s+0\s+1\s+1", summary);
-        Assert.Matches(@"R003\s+Bracket\s+7\s+2\s+5\s+0\s+1", summary);
+        Assert.Matches(@"3\s+Bracket\s+7\s+2\s+5\s+0\s+1", summary);
-        Assert.Matches(@"R004\s+Unplaced\s+3\s+0\s+3\s+0\s+-", summary);
+        Assert.Matches(@"4\s+Unplaced\s+3\s+0\s+3\s+0\s+-", summary);
         Assert.Contains("Page 1 of 2", summary);
+        Assert.Matches(@"Stock size\s+Quantity\s+Parts per plate", summary);
+        Assert.DoesNotMatch(@"\bR\d+\b", summary + plate);
+        Assert.DoesNotContain("Copies", summary + plate);
+        Assert.DoesNotContain("Parts/sheet", summary + plate);
 
         Assert.Contains("Plate 1", plate);
         Assert.Contains("Report test job", plate);
-        Assert.Matches(@"Copies:\s+2", plate);
+        Assert.Matches(@"Quantity:\s+2", plate);
-        Assert.Matches(@"R001\s+Bracket\s+2\s+4", plate);
+        Assert.Matches(@"1\s+Bracket\s+2\s+4", plate);
-        Assert.Matches(@"R002\s+Rotated\s+1\s+2", plate);
+        Assert.Matches(@"2\s+Rotated\s+1\s+2", plate);
-        Assert.Matches(@"R003\s+Bracket\s+1\s+2", plate);
+        Assert.Matches(@"3\s+Bracket\s+1\s+2", plate);
-        Assert.DoesNotContain("R004", plate);
+        Assert.DoesNotMatch(@"(?m)^4\s+Unplaced", plate);
         Assert.DoesNotContain("Cutoff test", plate + summary);
         Assert.Contains("not a dimensioned cutting drawing", plate);
         Assert.Contains("not a geometry or CNC approval", plate);
@@ -75,6 +79,7 @@ public sealed class NestPdfWriterTests : IDisposable
     public void Write_EmptyAndDemandOnlyJobsProduceExplicitSummaryOnlyReports()
     {
         var nest = new Nest("Empty test") { Units = Units.Millimeters };
+        nest.Plates.Add(new Plate(24, 48) { Quantity = 1 });
         var empty = ReportPdf.Text(WriteReport(nest, "empty.pdf"), 1);
         Assert.Contains("No plates in this job.", empty);
         Assert.Contains("No parts in this job.", empty);
@@ -83,10 +88,25 @@ public sealed class NestPdfWriterTests : IDisposable
         nest.Drawings.Add(NestReportTestData.Rectangle("Alpha", 20, 10, 2));
         var demand = ReportPdf.Text(WriteReport(nest, "demand.pdf"), 1);
         Assert.Contains("No plates in this job.", demand);
-        Assert.Matches(@"R001\s+Alpha\s+2\s+0\s+2\s+0\s+-", demand);
+        Assert.Matches(@"1\s+Alpha\s+2\s+0\s+2\s+0\s+-", demand);
         Assert.Contains("Page 1 of 1", demand);
     }
 
+    [SkippableFact]
+    public void Write_TrailingEmptyStockDoesNotAddPagesOrCountTowardTotals()
+    {
+        var nest = NestReportTestData.CreateMultiPlateNest();
+        var expected = ReportPdf.Pages(WriteReport(nest, "without-empty-stock.pdf"));
+        nest.Plates.Add(new Plate(24, 48) { Quantity = 5 });
+        nest.Plates.Add(new Plate(30, 60) { Quantity = 2 });
+        var before = NestReportBuilderTests.Fingerprint(nest);
+
+        var actual = ReportPdf.Pages(WriteReport(nest));
+
+        Assert.Equal(expected, actual);
+        Assert.Equal(before, NestReportBuilderTests.Fingerprint(nest));
+    }
+
     [Fact]
     public void Write_TabbedLeadInPartStrokesEachOpenContourSeparately()
     {
@@ -128,19 +148,25 @@ public sealed class NestPdfWriterTests : IDisposable
         Assert.Equal(new[] { path }, Directory.GetFiles(directory));
     }
 
+    [SkippableFact]
+    public void Write_UnlabelableTinyPartKeepsItsTableRowWithoutAddingPages()
+    {
+        var nest = NestReportTestData.CreateMultiPlateNest();
+        nest.Plates[3].Parts.Add(new Part(NestReportTestData.Rectangle("Tiny", 0.01, 0.01), new Vector(44, 20)));
+        var pages = ReportPdf.Pages(WriteReport(nest));
+        Assert.Equal(5, pages.Length);
+        Assert.Matches(@"4\s+Tiny\s+1\s+1", pages[4]);
+        Assert.DoesNotContain("detail", string.Join("\n", pages));
+    }
+
     [Theory]
-    [InlineData("illegible-label", "Plate 4, part 2 (R004)")]
+    [InlineData("cell-overflow", "Drawing 2")]
-    [InlineData("cell-overflow", "Drawing R002")]
     [InlineData("header-overflow", "Page header")]
     public void Write_UnsupportedLayoutFailsBeforeReplacingDestination(string scenario, string identified)
     {
         var nest = NestReportTestData.CreateMultiPlateNest();
         switch (scenario)
         {
-            case "illegible-label":
-                // Too small for a legible label even in a detail view, on the LAST plate.
-                nest.Plates[3].Parts.Add(new Part(NestReportTestData.Rectangle("Tiny", 0.01, 0.01), new Vector(44, 20)));
-                break;
             case "cell-overflow":
                 // A row taller than a page would be silently clipped by MigraDoc.
                 nest.Plates[0].Parts[2].BaseDrawing.Name = string.Concat(Enumerable.Repeat("0123456789", 60));
@@ -174,7 +200,7 @@ public sealed class NestPdfWriterTests : IDisposable
 
         var error = Assert.Throws<InvalidOperationException>(() => NestPdfWriter.Write(snapshot, path));
 
-        Assert.Contains("R002", error.Message);
+        Assert.Contains("2", error.Message);
         Assert.Contains("U+4E2D", error.Message);
         Assert.Equal("keep", File.ReadAllText(path));
         Assert.Equal(new[] { path }, Directory.GetFiles(directory));

OpenNest.Tests/Reporting/NestReportBuilderTests.cs

@@ -22,7 +22,7 @@ public class NestReportBuilderTests
         Assert.Equal(0.125, snapshot.Thickness);
         Assert.Equal("in", snapshot.Units);
         Assert.Equal(NestReportTestData.GeneratedAt, snapshot.GeneratedAt);
-        Assert.Equal(new[] { "R001", "R002", "R003", "R004" }, snapshot.Drawings.Select(d => d.Id));
+        Assert.Equal(new[] { "1", "2", "3", "4" }, snapshot.Drawings.Select(d => d.Id));
         Assert.Equal(new[] { "Bracket", "Rotated", "Bracket", "Unplaced" }, snapshot.Drawings.Select(d => d.Name));
         Assert.Equal(new long[] { 5, 1, 7, 3 }, snapshot.Drawings.Select(d => d.Required));
         Assert.Equal(new long[] { 4, 2, 2, 0 }, snapshot.Drawings.Select(d => d.Nested));
@@ -31,7 +31,7 @@ public class NestReportBuilderTests
         Assert.All(snapshot.Drawings.Take(3), d => Assert.Equal(new[] { 1 }, d.Plates));
         Assert.Empty(snapshot.Drawings[3].Plates);
         var plate = Assert.Single(snapshot.Plates);
-        Assert.Equal(new[] { "R001", "R001", "R002", "R003" }, plate.Parts.Select(p => p.ReportId));
+        Assert.Equal(new[] { "1", "1", "2", "3" }, plate.Parts.Select(p => p.ReportId));
         Assert.Single(plate.Cutoffs);
         Assert.Equal(2, snapshot.TotalSheets);
         Assert.Equal(new ReportBounds(0, 0, 48, 24), plate.Bounds);

OpenNest.Tests/Reporting/NestReportTestData.cs

@@ -49,8 +49,8 @@ public static class NestReportTestData
     }
 
     /// <summary>
-    /// Four layouts: "Bracket" R001 on plates 1, 2 and 4; R002 on plates 1 and 3; the distinct
+    /// Four layouts: "Bracket" 1 on plates 1, 2 and 4; 2 on plates 1 and 3; the distinct
-    /// same-named "Bracket" R003 on plates 1 and 3; R004 demanded but unplaced.
+    /// same-named "Bracket" 3 on plates 1 and 3; 4 demanded but unplaced.
     /// </summary>
     public static Nest CreateMultiPlateNest()
     {
@@ -73,7 +73,7 @@ public static class NestReportTestData
 
     /// <summary>
     /// One 120 x 60 sheet: two large parts and a cluster of tiny holed washers whose IDs cannot
-    /// be labeled legibly at overview scale, so they need detail views.
+    /// be labeled legibly at overview scale, so they share a group label.
     /// </summary>
     public static Nest CreateDenseNest()
     {

OpenNest.Tests/Reporting/ReportPdf.cs

@@ -28,22 +28,36 @@ public static class ReportPdf
         }
     }
 
-    /// <summary>Layout text of one page; skipped where poppler-utils is not installed.</summary>
+    /// <summary>Visual-row text of one page; bbox coordinates avoid platform-specific -layout order.</summary>
     public static string Text(string path, int page) =>
-        Regex.Replace(Run("pdftotext", "-layout", "-f", Page(page), "-l", Page(page), path, "-"), "[ \t]+\n", "\n");
+        LayoutPage(Run("pdftotext", "-bbox", "-f", Page(page), "-l", Page(page), path, "-"));
 
-    /// <summary>Every page's layout text, in order.</summary>
+    /// <summary>Every page's visual-row text, in order.</summary>
     public static string[] Pages(string path)
     {
-        var pages = Run("pdftotext", "-layout", path, "-").Split('\f');
+        var html = Run("pdftotext", "-bbox", path, "-");
-        // pdftotext terminates the last page with a form feed.
+        return Regex.Matches(html, @"<page\b[^>]*>.*?</page>", RegexOptions.Singleline)
-        return pages.Take(pages.Length - 1).Select(page => Regex.Replace(page, "[ \t]+\n", "\n")).ToArray();
+            .Select(match => LayoutPage(match.Value)).ToArray();
+    }
+
+    private static string LayoutPage(string html)
+    {
+        var rows = new List<(double Top, List<(double Left, string Text)> Words)>();
+        foreach (var word in ParseWords(html).OrderBy(word => word.Top).ThenBy(word => word.Left))
+        {
+            if (rows.Count == 0 || System.Math.Abs(word.Top - rows[^1].Top) > 1.5)
+                rows.Add((word.Top, []));
+            rows[^1].Words.Add((word.Left, word.Text));
+        }
+        return string.Join("\n", rows.Select(row => string.Join(" ", row.Words.OrderBy(word => word.Left).Select(word => word.Text)))) + "\n";
     }
 
     /// <summary>Words with page-space boxes (points, Y down).</summary>
-    public static List<(double Left, double Top, double Right, double Bottom, string Text)> Words(string path, int page)
+    public static List<(double Left, double Top, double Right, double Bottom, string Text)> Words(string path, int page) =>
+        ParseWords(Run("pdftotext", "-bbox", "-f", Page(page), "-l", Page(page), path, "-"));
+
+    private static List<(double Left, double Top, double Right, double Bottom, string Text)> ParseWords(string xml)
     {
-        var xml = Run("pdftotext", "-bbox", "-f", Page(page), "-l", Page(page), path, "-");
         return Regex.Matches(xml, "<word xMin=\"([\\d.]+)\" yMin=\"([\\d.]+)\" xMax=\"([\\d.]+)\" yMax=\"([\\d.]+)\">([^<]*)</word>")
             .Select(match => (Number(match.Groups[1].Value), Number(match.Groups[2].Value), Number(match.Groups[3].Value),
                 Number(match.Groups[4].Value), System.Net.WebUtility.HtmlDecode(match.Groups[5].Value)))

OpenNest.Tests/Sequencing/ManualPartSequencingTests.cs

@@ -0,0 +1,43 @@
+using OpenNest.Geometry;
+using OpenNest.Sequencing;
+
+namespace OpenNest.Tests.Sequencing;
+
+public class ManualPartSequencingTests
+{
+    [Fact]
+    public void Move_SetsExactOneBasedSequenceWithoutChangingQuantity()
+    {
+        var drawing = TestHelpers.MakeSquareDrawing();
+        var first = new Part(drawing, new Vector(0, 0));
+        var second = new Part(drawing, new Vector(20, 0));
+        var third = new Part(drawing, new Vector(40, 0));
+        var plate = TestHelpers.MakePlate(60, 120, first, second, third);
+        var nested = drawing.Quantity.Nested;
+        var reorders = 0;
+        plate.PartsReordered += (_, _) => reorders++;
+
+        Assert.True(ManualPartSequencing.Move(plate, third, 1));
+        Assert.Equal(new[] { third, first, second }, plate.Parts);
+        Assert.True(ManualPartSequencing.Move(plate, first, 3));
+        Assert.Equal(new[] { third, second, first }, plate.Parts);
+        Assert.Equal(nested, drawing.Quantity.Nested);
+        Assert.Equal(2, reorders);
+    }
+
+    [Fact]
+    public void Move_RejectsAbsentPartAndOutOfRangeWithoutChangingPlate()
+    {
+        var drawing = TestHelpers.MakeSquareDrawing();
+        var part = new Part(drawing, new Vector(0, 0));
+        var plate = TestHelpers.MakePlate(60, 120, part);
+        var reorders = 0;
+        plate.PartsReordered += (_, _) => reorders++;
+
+        Assert.False(ManualPartSequencing.Move(plate, part, 0));
+        Assert.False(ManualPartSequencing.Move(plate, part, 2));
+        Assert.False(ManualPartSequencing.Move(plate, new Part(drawing, new Vector(0, 0)), 1));
+        Assert.Equal(new[] { part }, plate.Parts);
+        Assert.Equal(0, reorders);
+    }
+}

OpenNest.WinForms.Tests/EtchDisplayTests.cs

@@ -0,0 +1,262 @@
+using System.Drawing;
+using System.Drawing.Drawing2D;
+using OpenNest.CNC;
+using OpenNest.Controls;
+using OpenNest.Geometry;
+using Program = OpenNest.CNC.Program;
+
+namespace OpenNest.WinForms.Tests;
+
+public class EtchDisplayTests
+{
+    private static readonly Color EtchColor = Color.Lime;
+    private static readonly Color CutColor = Color.FromArgb(48, 48, 48);
+    private static readonly Color PartColor = Color.FromArgb(216, 49, 49);
+
+    [Theory]
+    [InlineData(false, false, Mode.Absolute)]
+    [InlineData(false, true, Mode.Absolute)]
+    [InlineData(true, false, Mode.Absolute)]
+    [InlineData(true, true, Mode.Absolute)]
+    [InlineData(false, false, Mode.Incremental)]
+    [InlineData(false, true, Mode.Incremental)]
+    [InlineData(true, false, Mode.Incremental)]
+    [InlineData(true, true, Mode.Incremental)]
+    public void PlateSeparatesEtchFromCutWithoutChangingProgram(bool leads, bool selected, Mode mode)
+        => StaTestThread.Run(() =>
+        {
+            var program = MixedProgram();
+            program.Mode = mode;
+            var before = Snapshot(program);
+            var drawing = new Drawing("Synthetic etch display", program) { Color = PartColor };
+            var part = new Part(drawing, new Vector(10, 10)) { HasManualLeadIns = leads };
+            using var view = new PlateView(ColorSchemeRegistry.Get("Workshop"));
+            view.Matrix = new Matrix();
+            var layout = LayoutPart.Create(part, view);
+            layout.IsSelected = selected;
+            using var image = new Bitmap(130, 130);
+            using var g = Graphics.FromImage(image);
+            g.Clear(Color.White);
+            layout.Draw(g);
+
+            var renderedFill = image.GetPixel(20, 20);
+            if (!selected)
+                Assert.Equal(PartColor.ToArgb(), renderedFill.ToArgb());
+            else
+                Assert.NotEqual(PartColor.ToArgb(), renderedFill.ToArgb());
+            Assert.True(Luminance(CutColor) < Luminance(renderedFill));
+            Assert.True(Distinctness(EtchColor, renderedFill) >= 15);
+            // A closed etch is not a hole; an actual closed cut still is.
+            Assert.Equal(image.GetPixel(20, 20), image.GetPixel(40, 40));
+            Assert.Equal(Color.White.ToArgb(), image.GetPixel(90, 90).ToArgb());
+            Assert.Equal(EtchColor.ToArgb(), image.GetPixel(30, 40).ToArgb());
+            Assert.Equal(EtchColor.ToArgb(), image.GetPixel(40, 70).ToArgb());
+            Assert.Equal(EtchColor.ToArgb(), image.GetPixel(75, 40).ToArgb());
+            Assert.Equal(CutColor.ToArgb(), image.GetPixel(10, 50).ToArgb());
+            Assert.Equal(CutColor.ToArgb(), image.GetPixel(80, 90).ToArgb());
+            // Suppression must not leave a visible cut or etch stroke.
+            Assert.Equal(image.GetPixel(20, 20), image.GetPixel(40, 90));
+            Assert.Equal(before, Snapshot(program));
+        }, TimeSpan.FromMinutes(1), "Etch display test timed out.");
+
+    [Fact]
+    public void ActualCutWinsWhenEtchOccupiesTheSameLine() => StaTestThread.Run(() =>
+    {
+        var program = MixedProgram();
+        program.MoveTo(20, 60);
+        program.Codes.Add(new LinearMove(40, 60) { Layer = LayerType.Cut });
+        using var view = new PlateView(ColorSchemeRegistry.Get("Workshop"));
+        view.Matrix = new Matrix();
+        var layout = LayoutPart.Create(new Part(new Drawing("Overlaid cut", program)), view);
+        using var image = new Bitmap(120, 120);
+        using var g = Graphics.FromImage(image);
+        layout.Draw(g);
+        Assert.Equal(CutColor.ToArgb(), image.GetPixel(30, 60).ToArgb());
+    }, TimeSpan.FromMinutes(1), "Overlaid cut test timed out.");
+
+    [Fact]
+    public void ThumbnailKeepsEtchOutOfFillAndUsesDedicatedColor()
+    {
+        var program = MixedProgram();
+        using var fill = new SolidBrush(Color.FromArgb(184, 207, 224));
+        using var image = (Bitmap)program.GetImage(new System.Drawing.Size(110, 110), Pens.Black, fill);
+        Assert.Equal(image.GetPixel(15, 95), image.GetPixel(35, 75));
+        Assert.Equal(0, image.GetPixel(85, 25).A);
+        Assert.Equal(ColorScheme.Default.EtchColor.ToArgb(), image.GetPixel(25, 75).ToArgb());
+        Assert.Equal(Color.Black.ToArgb(), image.GetPixel(75, 25).ToArgb());
+    }
+
+    [Fact]
+    public void PlateRendererKeepsEtchesInNumberedPartsAndPlacementPreviews() => StaTestThread.Run(() =>
+    {
+        using var view = new PlateView(ColorSchemeRegistry.Get("Workshop"))
+        {
+            Size = new System.Drawing.Size(250, 130),
+            DrawBounds = false,
+        };
+        view.Matrix = new Matrix();
+        view.Plate.Parts.Add(new Part(new Drawing("Placed", MixedProgram())));
+        view.Previews.SetActiveParts(new List<Part>
+        {
+            new(new Drawing("Preview", MixedProgram()), new Vector(120, 0)),
+        });
+        using var image = new Bitmap(250, 130);
+        using var g = Graphics.FromImage(image);
+        g.Clear(Color.White);
+        view.Renderer.DrawParts(g);
+        Assert.Equal(EtchColor.ToArgb(), image.GetPixel(20, 30).ToArgb());
+        Assert.Equal(EtchColor.ToArgb(), image.GetPixel(140, 30).ToArgb());
+        Assert.Equal(CutColor.ToArgb(), image.GetPixel(0, 50).ToArgb());
+    }, TimeSpan.FromMinutes(1), "Plate preview test timed out.");
+
+    [Fact]
+    public void WorkshopIsAnAdditionalPaletteNotAReplacementForSavedSchemes()
+    {
+        var scheme = ColorSchemeRegistry.Get("Workshop");
+        Assert.Equal("Workshop", scheme.Name);
+        Assert.Equal("Classic", ColorSchemeRegistry.Get("Classic").Name);
+        Assert.Equal("Pastel", ColorSchemeRegistry.Get("Pastel").Name);
+        Assert.Equal("Dark", ColorSchemeRegistry.Get("Dark").Name);
+        Assert.NotEmpty(scheme.PartColors);
+        Assert.True(scheme.UseGoldenAngleColors);
+        Assert.Equal(PartColor, scheme.PartColors[0]);
+        Assert.Equal(Color.FromArgb(242, 242, 242), scheme.LayoutFillColor);
+        Assert.True(scheme.SelectedPartColor.IsEmpty);
+        Assert.All(Enumerable.Range(0, 1000).Select(PartColorPalette.GoldenAngle), color =>
+        {
+            Assert.True(Distinctness(color, EtchColor) >= 15, "Etch must stay distinguishable from generated fills.");
+            Assert.True(Distinctness(color, CutColor) >= 15, "Cuts must stay distinguishable from generated fills.");
+        });
+    }
+
+    [Fact]
+    public void SchemeRoundTripAndOldFilesPreserveOutlineFallback()
+    {
+        var workshop = ColorSchemeRegistry.Get("Workshop");
+        var restored = ColorSchemeSerializer.Deserialize(ColorSchemeSerializer.Serialize(workshop));
+        Assert.Equal(CutColor.ToArgb(), restored.PartOutlineColor.ToArgb());
+        Assert.Equal(EtchColor.ToArgb(), restored.EtchColor.ToArgb());
+        Assert.True(restored.SelectedPartColor.IsEmpty);
+        Assert.True(restored.UseGoldenAngleColors);
+        Assert.Equal(workshop.PartColors.Select(c => c.ToArgb()), restored.PartColors.Select(c => c.ToArgb()));
+        var legacy = System.Text.Json.Nodes.JsonNode.Parse(ColorSchemeSerializer.Serialize(ColorSchemeRegistry.Get("Classic")))!.AsObject();
+        legacy.Remove("etchColor");
+        legacy.Remove("partOutlineColor");
+        legacy.Remove("selectedPartColor");
+        legacy.Remove("useGoldenAngleColors");
+        var oldScheme = ColorSchemeSerializer.Deserialize(legacy.ToJsonString());
+        Assert.True(oldScheme.PartOutlineColor.IsEmpty);
+        Assert.True(oldScheme.SelectedPartColor.IsEmpty);
+        Assert.False(oldScheme.UseGoldenAngleColors);
+        Assert.Equal(System.Windows.Forms.ControlPaint.Dark(Color.Coral), oldScheme.GetPartOutlineColor(Color.Coral));
+        Assert.Equal(new ColorScheme().EtchColor.ToArgb(), oldScheme.EtchColor.ToArgb());
+    }
+
+    [Fact]
+    public void PaletteChangeRepaintsExistingPartWithoutMovingIt() => StaTestThread.Run(() =>
+    {
+        var scheme = ColorSchemeSerializer.Deserialize(ColorSchemeSerializer.Serialize(ColorSchemeRegistry.Get("Classic")));
+        var drawing = new Drawing("Recolor", MixedProgram()) { Color = Color.Coral };
+        using var view = new PlateView(scheme);
+        view.Matrix = new Matrix();
+        var layout = LayoutPart.Create(new Part(drawing), view);
+        var path = layout.Path;
+        scheme.PartOutlineColor = CutColor;
+        scheme.EtchColor = EtchColor;
+        drawing.Color = Color.FromArgb(184, 207, 224);
+        using var image = new Bitmap(120, 120);
+        using var g = Graphics.FromImage(image);
+        layout.Draw(g);
+        Assert.Same(path, layout.Path);
+        Assert.Equal(drawing.Color.ToArgb(), image.GetPixel(10, 10).ToArgb());
+        Assert.Equal(CutColor.ToArgb(), image.GetPixel(0, 50).ToArgb());
+        Assert.Equal(EtchColor.ToArgb(), image.GetPixel(20, 30).ToArgb());
+    }, TimeSpan.FromMinutes(1), "Scheme repaint test timed out.");
+
+    [Fact]
+    public void LayerChangesAndSubprogramsDoNotCreateConnectingStrokes()
+    {
+        var program = new Program();
+        program.MoveTo(10, 10);
+        program.Codes.Add(new LinearMove(20, 10) { Layer = LayerType.Cut });
+        program.Codes.Add(new LinearMove(30, 10) { Layer = LayerType.Scribe });
+        program.Codes.Add(new LinearMove(40, 10) { Layer = LayerType.Cut });
+        program.Codes.Add(new LinearMove(50, 10) { Layer = LayerType.Leadin });
+        program.Codes.Add(new LinearMove(60, 10) { Layer = LayerType.Leadout });
+        var child = new Program(Mode.Incremental);
+        child.MoveTo(2, 3);
+        child.Codes.Add(new LinearMove(6, 0) { Layer = LayerType.Scribe });
+        program.Codes.Add(new SubProgramCall(child, 0) { Offset = new Vector(70, 20) });
+        var before = Snapshot(program);
+        program.GetDisplayPaths(new Vector(5, 5), out var cuts, out var leads, out var etches);
+        using (cuts)
+        using (leads)
+        using (etches)
+        using (var pen = new Pen(Color.Black, 1))
+        {
+            Assert.True(cuts.IsOutlineVisible(20, 15, pen));
+            Assert.True(cuts.IsOutlineVisible(40, 15, pen));
+            Assert.False(cuts.IsOutlineVisible(30, 15, pen));
+            Assert.True(etches.IsOutlineVisible(30, 15, pen));
+            Assert.False(etches.IsOutlineVisible(40, 15, pen));
+            Assert.True(leads.IsOutlineVisible(50, 15, pen));
+            Assert.True(leads.IsOutlineVisible(60, 15, pen));
+            Assert.False(cuts.IsOutlineVisible(50, 15, pen));
+            Assert.True(etches.IsOutlineVisible(80, 28, pen));
+            Assert.False(etches.IsOutlineVisible(60, 21, pen));
+        }
+        Assert.Equal(before, Snapshot(program));
+    }
+
+    private static double Contrast(Color a, Color b)
+    {
+        var first = Luminance(a);
+        var second = Luminance(b);
+        return (System.Math.Max(first, second) + 0.05) / (System.Math.Min(first, second) + 0.05);
+    }
+
+    private static double Luminance(Color color)
+    {
+        static double Linear(byte channel)
+        {
+            var value = channel / 255.0;
+            return value <= 0.04045 ? value / 12.92 : System.Math.Pow((value + 0.055) / 1.055, 2.4);
+        }
+        return 0.2126 * Linear(color.R) + 0.7152 * Linear(color.G) + 0.0722 * Linear(color.B);
+    }
+
+    private static double Distinctness(Color a, Color b) => System.Math.Sqrt(
+        (a.R - (double)b.R) * (a.R - b.R)
+        + (a.G - (double)b.G) * (a.G - b.G)
+        + (a.B - (double)b.B) * (a.B - b.B));
+
+    private static Program MixedProgram()
+    {
+        var program = new Program();
+        AddSquare(program, 0, 0, 100, LayerType.Cut);
+        AddSquare(program, 20, 20, 20, LayerType.Scribe);
+        AddSquare(program, 70, 70, 20, LayerType.Cut);
+        program.MoveTo(20, 60);
+        program.Codes.Add(new LinearMove(40, 60) { Layer = LayerType.Scribe });
+        program.MoveTo(65, 30);
+        program.Codes.Add(new ArcMove(65, 30, 60, 30) { Layer = LayerType.Scribe });
+        program.MoveTo(20, 80);
+        program.Codes.Add(new LinearMove(40, 80) { Layer = LayerType.Scribe, Suppressed = true });
+        return program;
+    }
+
+    private static void AddSquare(Program program, double x, double y, double size, LayerType layer)
+    {
+        program.MoveTo(x, y);
+        foreach (var end in new[] { new Vector(x + size, y), new Vector(x + size, y + size), new Vector(x, y + size), new Vector(x, y) })
+            program.Codes.Add(new LinearMove(end) { Layer = layer });
+    }
+
+    private static string[] Snapshot(Program program) => program.Codes.Select(code => code switch
+    {
+        ArcMove arc => $"arc:{arc.Layer}:{arc.Suppressed}:{arc.EndPoint.X:R}:{arc.EndPoint.Y:R}:{arc.CenterPoint.X:R}:{arc.CenterPoint.Y:R}:{arc.Rotation}",
+        LinearMove line => $"line:{line.Layer}:{line.Suppressed}:{line.EndPoint.X:R}:{line.EndPoint.Y:R}",
+        Motion motion => $"{motion.Type}:{motion.Suppressed}:{motion.EndPoint.X:R}:{motion.EndPoint.Y:R}",
+        _ => code.ToString()!
+    }).Prepend(program.Mode.ToString()).ToArray();
+}

OpenNest.WinForms.Tests/EtchVisibilityTests.cs

@@ -0,0 +1,94 @@
+using System.Drawing;
+using System.Drawing.Drawing2D;
+using System.Reflection;
+using OpenNest.CNC;
+using OpenNest.Controls;
+using OpenNest.Geometry;
+
+namespace OpenNest.WinForms.Tests;
+
+public class EtchVisibilityTests
+{
+    [Theory]
+    [InlineData(false, false)]
+    [InlineData(false, true)]
+    [InlineData(true, false)]
+    [InlineData(true, true)]
+    public void EtchRemainsVisibleWhenNoCutIntersectsViewport(bool includeCut, bool preview)
+        => StaTestThread.Run(() =>
+        {
+            var program = new CNC.Program();
+            if (includeCut)
+                AddSquare(program, 0, LayerType.Cut);
+            AddSquare(program, 100, LayerType.Scribe);
+            var part = new Part(new Drawing("Panned etch", program));
+            using var view = new PannedView();
+            if (preview)
+                view.Previews.SetActiveParts(new List<Part> { part });
+            else
+                view.Plate.Parts.Add(part);
+            var layout = preview ? Assert.Single(view.PreviewParts) : Assert.Single(view.LayoutParts);
+            Assert.False(layout.Path.GetBounds().IntersectsWith(view.GetViewBounds()));
+            using var image = new Bitmap(30, 30);
+            using var g = Graphics.FromImage(image);
+            g.Clear(Color.White);
+            g.TranslateTransform(-95, -95);
+            view.Renderer.DrawParts(g);
+            Assert.Equal(Color.Lime.ToArgb(), image.GetPixel(5, 15).ToArgb());
+            Assert.Equal(Color.White.ToArgb(), image.GetPixel(8, 8).ToArgb());
+            if (!includeCut)
+                Assert.Equal(0, layout.Path.PointCount);
+        }, TimeSpan.FromMinutes(1), "Panned etch test timed out.");
+
+    [Fact]
+    public void EtchOnlyPart_RemainsSelectableAndHoverableWithoutCutMaterial()
+        => StaTestThread.Run(() =>
+        {
+            var program = new CNC.Program();
+            AddSquare(program, 100, LayerType.Scribe);
+            var part = new Part(new Drawing("etch-only", program));
+            using var view = new PannedView();
+            view.Plate.Parts.Add(part);
+            var layout = Assert.Single(view.LayoutParts);
+            Assert.Equal(0, layout.Path.PointCount);
+            Assert.True(layout.EtchPath.PointCount > 0);
+
+            Assert.Same(layout, view.Selection.GetPartAtGraphPoint(new PointF(110, 110)));
+            Assert.Null(view.Selection.GetPartAtGraphPoint(new PointF(50, 50)));
+            Assert.Contains(layout, view.Selection.GetPartsFromWindow(
+                new RectangleF(105, 105, 10, 10), SelectionType.Intersect));
+            Assert.Contains(layout, view.Selection.GetPartsFromWindow(
+                new RectangleF(95, 95, 30, 30), SelectionType.Contains));
+
+            typeof(PlateView).GetField("hoverPending", BindingFlags.Instance | BindingFlags.NonPublic)!
+                .SetValue(view, true);
+            typeof(PlateView).GetField("hoverPoint", BindingFlags.Instance | BindingFlags.NonPublic)!
+                .SetValue(view, new Point(15, 15));
+            typeof(PlateView).GetMethod("HoverCheck", BindingFlags.Instance | BindingFlags.NonPublic)!
+                .Invoke(view, null);
+            Assert.Same(layout, typeof(PlateView).GetField("hoveredPart",
+                BindingFlags.Instance | BindingFlags.NonPublic)!.GetValue(view));
+        }, TimeSpan.FromMinutes(1), "Etch selection test timed out.");
+
+    private static void AddSquare(CNC.Program program, double origin, LayerType layer)
+    {
+        program.MoveTo(origin, origin);
+        foreach (var end in new[]
+        {
+            new Vector(origin + 20, origin), new Vector(origin + 20, origin + 20),
+            new Vector(origin, origin + 20), new Vector(origin, origin),
+        })
+            program.Codes.Add(new LinearMove(end) { Layer = layer });
+    }
+
+    private sealed class PannedView : PlateView
+    {
+        public PannedView() : base(ColorSchemeRegistry.Get("Workshop"))
+        {
+            Size = new System.Drawing.Size(30, 30);
+            DrawBounds = false;
+            Matrix = new Matrix();
+            origin = new PointF(-95, -95);
+        }
+    }
+}

OpenNest.WinForms.Tests/Forms/AutoNestFormStockOptionsTests.cs

@@ -10,6 +10,94 @@ namespace OpenNest.WinForms.Tests.Forms;
 
 public class AutoNestFormStockOptionsTests
 {
+    [Theory]
+    [InlineData("invalid", false)]
+    [InlineData("-1", false)]
+    [InlineData("NaN", false)]
+    [InlineData("27", true)]
+    public void PendingCostEditsAreValidatedBeforePublishing(string text, bool valid)
+    {
+        RunSta(() =>
+        {
+            using var form = new AutoNestForm(new Nest());
+            form.LoadPlateOptions(new List<PlateOption> { new() { Width = 48, Length = 96, Cost = 5 } }, 0.5);
+            var grid = GetGrid(form);
+            ((TabControl)form.Controls.Find("tabControl", true).Single()).SelectedIndex = 1;
+            form.Show();
+            grid.Focus();
+            grid.CurrentCell = grid.Rows[0].Cells[1];
+            Assert.True(grid.BeginEdit(false));
+            grid.EditingControl.Text = text;
+            Assert.Equal(valid, form.TryGetPlateOptions(out var options, out var error));
+            if (valid)
+                Assert.Equal(27, Assert.Single(options).Cost);
+            else
+            {
+                Assert.Empty(options);
+                Assert.Contains("cost", error);
+            }
+            grid.CancelEdit();
+        });
+    }
+
+    [Theory]
+    [InlineData(0, 0, true)]
+    [InlineData(5, 8, true)]
+    [InlineData(5, 0, false)]
+    [InlineData(0, 5, false)]
+    [InlineData(-1, -1, false)]
+    [InlineData(double.NaN, 5, false)]
+    [InlineData(double.PositiveInfinity, 5, false)]
+    public void CostRowsRequireConsistentFiniteValues(double first, double second, bool valid)
+    {
+        RunSta(() =>
+        {
+            using var form = new AutoNestForm(new Nest());
+            form.LoadPlateOptions(new List<PlateOption>
+            {
+                new() { Width = 48, Length = 96, Cost = first },
+                new() { Width = 60, Length = 120, Cost = second },
+            }, 0.5);
+            Assert.Equal(valid, form.TryGetPlateOptions(out var options, out var error));
+            if (!valid)
+            {
+                Assert.Empty(options);
+                Assert.Contains("cost", error);
+            }
+            AssertNewRow(GetGrid(form));
+        });
+    }
+
+    [Theory]
+    [InlineData(false)]
+    [InlineData(true)]
+    public void StockRowsCanBeSelectedAndRemoved(bool loadSavedOptions)
+    {
+        RunSta(() =>
+        {
+            using var form = new AutoNestForm(new Nest());
+            if (loadSavedOptions)
+                form.LoadPlateOptions(new List<PlateOption>
+                {
+                    new() { Width = 48, Length = 96, Cost = 25 },
+                    new() { Width = 60, Length = 120, Cost = 40 },
+                }, 0.5);
+            form.OptimizePlateSize = true;
+            var grid = GetGrid(form);
+
+            Assert.True(grid.RowHeadersVisible);
+            Assert.True(grid.AllowUserToDeleteRows);
+            Assert.Equal(DataGridViewSelectionMode.RowHeaderSelect, grid.SelectionMode);
+            grid.Rows[0].Selected = true;
+            Assert.True(grid.Rows[0].Selected);
+
+            var remaining = form.GetPlateOptions().Count;
+            Assert.IsAssignableFrom<IList>(grid.DataSource).RemoveAt(grid.SelectedRows[0].Index);
+            Assert.Equal(remaining - 1, form.GetPlateOptions().Count);
+            AssertNewRow(grid);
+        });
+    }
+
     [Theory]
     [InlineData(false)]
     [InlineData(true)]
@@ -32,7 +120,7 @@ public class AutoNestFormStockOptionsTests
             Assert.True(rows.AllowNew);
             var added = rows.AddNew()!;
             SetValue(added, "Size", "84 x 168");
-            SetValue(added, "Cost", 123.5);
+            SetValue(added, "Cost", loadSavedOptions ? 123.5 : 0);
             ((ICancelAddNew)rows).EndNew(rows.Count - 1);
 
             var options = form.GetPlateOptions();
@@ -40,7 +128,7 @@ public class AutoNestFormStockOptionsTests
             var option = options.Last();
             Assert.Equal(84, option.Width);
             Assert.Equal(168, option.Length);
-            Assert.Equal(123.5, option.Cost);
+            Assert.Equal(loadSavedOptions ? 123.5 : 0, option.Cost);
             AssertNewRow(grid);
         });
     }
@@ -98,6 +186,7 @@ public class AutoNestFormStockOptionsTests
         var rows = Assert.IsAssignableFrom<IBindingList>(grid.DataSource);
         var row = rows.AddNew()!;
         SetValue(row, "Size", invalid);
+        SetValue(row, "Cost", 25);
         ((ICancelAddNew)rows).EndNew(rows.Count - 1);
 
         Assert.False(form.TryGetPlateOptions(out var options, out var error));