fix(engine): route restricted-rotation requirements to OrderedPlateNester

The legacy engine reads RotationStart == RotationEnd == 0 as
unconstrained and its Pairs/RectBestFit strategies rotate freely, so it
returned poses a Fixed/BoundedSweep RotationPolicy forbids and the job
validator threw. DefaultPlateNester now delegates such requests to the
policy-aware OrderedPlateNester.

Fixes RunAsync_FiniteStockExhaustion_PreservesUnplacedRequirementAndLockedRotation.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

OpenNest.Engine/Jobs/Placement/DefaultPlateNester.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using System.Threading;
 
 namespace OpenNest;
@@ -20,6 +21,7 @@ namespace OpenNest;
 public sealed class DefaultPlateNester : IPlateNester
 {
     private readonly Func<Plate, DefaultNestEngine> engineFactory;
+    private readonly OrderedPlateNester restrictedRotationNester = new();
     private readonly Dictionary<string, Drawing> drawingsById = new(StringComparer.Ordinal);
     private readonly Dictionary<Drawing, string> idByDrawing = new(
         ReferenceEqualityComparer.Instance
@@ -44,6 +46,13 @@ public sealed class DefaultPlateNester : IPlateNester
         ArgumentNullException.ThrowIfNull(request);
         token.ThrowIfCancellationRequested();
 
+        // The legacy engine cannot express a locked or bounded rotation (start == end == 0 reads
+        // as "unconstrained") and its Pairs/RectBestFit strategies rotate freely, so it can return
+        // poses the requirement's RotationPolicy forbids. Restricted requirements go to the
+        // policy-aware ordered nester, which only proposes allowed angles and validates each pose.
+        if (request.Parts.Any(part => part.Rotation.Kind != RotationPolicyKind.Automatic))
+            return restrictedRotationNester.Place(request, progress, token);
+
         var plate = DrawingJobMapper.CreatePlate(request.Stock);
         var items = new List<NestItem>(request.Parts.Count);
         foreach (var requirement in request.Parts)