fix(engine): record a committed clamp removal whatever the target sheet holds

SyncClampZones returned early when the empty target already held exactly the
solved reduced zones, and otherwise preferred the target's own rail over the
stock's, so a removal committed onto such a sheet kept no rail, removed ids
or time. The stock's rail now wins, and the rail/removal state is reconciled
even when the zones themselves need no replacement.

PM 60f7a673-455e-4a87-b865-a4806f417ee6

OpenNest.Engine.Tests/Jobs/ClampRemovalRepairTests.cs

@@ -279,4 +279,32 @@ public class ClampRemovalRepairTests
         Assert.Null(outcome);
         Assert.True(engine.Calls <= ClampRemovalRecovery.MaxProbeSolves, $"recovery made {engine.Calls} solves");
     }
+    // PM 60f7a673: the removal is recorded whatever the empty target sheet already holds.
+    [Theory]
+    [InlineData("reduced-explicit")] // no rail, already exactly the solved reduced zones
+    [InlineData("other-rail")]       // follows a different rail that cannot recreate them
+    public void CommittedRemovalIsRecordedOnAnyEmptyTarget(string target)
+    {
+        var drawing = new Drawing("wide", TestDrawingFactory.Rectangle(14, 3));
+        var nest = new Nest();
+        nest.Drawings.Add(drawing);
+        nest.PlateDefaults.Size = new Size(3, 23);
+        nest.PlateDefaults.EdgeSpacing = new Spacing(0, 0, 0, 0);
+        var plate = nest.CreatePlate();
+        if (target == "reduced-explicit")
+            plate.ClampZones.Add(Zones()[1]);
+        else
+            plate.SetClampRail(new ClampRail(2, 0.625, new[] { 6.0, 21.0 }));
+        using var manager = new PlateManager(nest);
+
+        var result = NestPipeline.Run(Request(Stock(), Item("wide", 14, 3, 1)));
+        Assert.True(result.IsValid, string.Join("; ", result.Violations));
+        var applied = Assert.Single(NestPipelineCommit.ApplyToEmptyPlates(result, manager));
+
+        Assert.Same(plate, applied);
+        Assert.Same(Rail, applied.ClampRail);
+        Assert.Equal(new[] { "clamp-1" }, applied.RemovedClamps);
+        Assert.Equal(new[] { "clamp-2" }, applied.ClampZones.Select(z => z.Id));
+        Assert.Equal(ClampRail.DefaultRemovalMinutes, applied.ClampRemovalMinutes);
+    }
 }

OpenNest.Engine/Jobs/NestPipelineCommit.cs

@@ -68,27 +68,29 @@ public static class NestPipelineCommit
     {
         var left = stock.Quadrant is 1 or 4 ? 0 : -stock.Size.Length;
         var bottom = stock.Quadrant is 1 or 2 ? 0 : -stock.Size.Width;
-        if (SameInPlacementFrame(plate.ClampZones, stock.ClampZones, left, bottom))
-            return;
-
-        // A plate without a rail still takes the rail its stock was resolved from, so a
-        // last-resort removal on that stock is never committed without naming the clamp.
-        var rail = plate.ClampRail ?? stock.ClampRail;
-        plate.SetClampRail(null); // explicit zones from here on
-        foreach (var zone in stock.ClampZones)
-            plate.ClampZones.Add(new ClampZone(zone.Id, zone.Bounds.Translate(-left, -bottom)));
+        // The rail the solved zones were resolved from wins over whatever the target follows;
+        // explicit stock keeps the target's own rail as before.
+        var rail = stock.ClampRail ?? plate.ClampRail;
+        if (!SameInPlacementFrame(plate.ClampZones, stock.ClampZones, left, bottom))
+        {
+            plate.SetClampRail(null); // explicit zones from here on
+            foreach (var zone in stock.ClampZones)
+                plate.ClampZones.Add(new ClampZone(zone.Id, zone.Bounds.Translate(-left, -bottom)));
+        }
         if (rail == null)
             return;
 
         // D8: the sheet's zones may be the rail's resolution for it minus clamps Auto Nest
         // removed as a last resort; derive which (if any) so the committed plate keeps
-        // following the rail - and the removal - through later resizes (C13).
+        // following the rail - and the removal - through later resizes (C13). This runs even
+        // when the target already held exactly these zones, so the removal is never lost.
         var kept = new HashSet<string>(plate.ClampZones.Select(z => z.Id), StringComparer.Ordinal);
         var removedClamps = rail.ResolveFor(plate.Size, plate.Quadrant)
             .Select(z => z.Id)
             .Where(id => !kept.Contains(id))
             .ToList();
-        if (rail.Matches(plate, removedClamps))
+        var unchanged = ReferenceEquals(plate.ClampRail, rail) && plate.RemovedClamps.SetEquals(removedClamps);
+        if (!unchanged && rail.Matches(plate, removedClamps))
             plate.SetClampRail(rail, removedClamps);
     }