feat(engine): rebind live fill previews to the drawing's original frame

DefaultPlateFiller runs its search in a canonical (MBR-axis-aligned)
copy of the drawing. Intermediate progress reports — the Nesting
Progress dialog, PlateView's active-parts overlay — were showing that
transient canonical orientation instead of the drawing's real one.

FillContext.OriginalDrawing carries the pre-canonicalization drawing
through the pipeline; ReportProgress rebinds reported parts to it via
CanonicalFrame.RebindToOriginal before they reach the UI. Uses a
shallow list copy rather than per-part Part.Clone() — Clone() re-derives
its target rotation from BaseDrawing.Program.Rotation + Rotation, which
would double-count the canonical drawing's baked source angle.

OpenNest.Engine/Jobs/Placement/Fillers/DefaultPlateFiller.cs

@@ -112,7 +112,7 @@ internal class DefaultPlateFiller : PlateFillerBase
                 );
         }
 
-        var best = RunFillPipeline(canonicalItem, effectiveWorkArea, progress, token);
+        var best = RunFillPipeline(canonicalItem, originalDrawing, effectiveWorkArea, progress, token);
 
         if (
             canonicalItem.Quantity > 0
@@ -125,7 +125,7 @@ internal class DefaultPlateFiller : PlateFillerBase
             );
             PhaseResults.Clear();
             AngleResults.Clear();
-            best = RunFillPipeline(canonicalItem, workArea, progress, token);
+            best = RunFillPipeline(canonicalItem, originalDrawing, workArea, progress, token);
         }
 
         if (canonicalItem.Quantity > 0 && best.Count > canonicalItem.Quantity)
@@ -333,6 +333,7 @@ internal class DefaultPlateFiller : PlateFillerBase
 
     private List<Part> RunFillPipeline(
         NestItem item,
+        Drawing originalDrawing,
         Box workArea,
         IProgress<NestProgress> progress,
         CancellationToken token
@@ -341,6 +342,7 @@ internal class DefaultPlateFiller : PlateFillerBase
         var context = new FillContext
         {
             Item = item,
+            OriginalDrawing = originalDrawing,
             WorkArea = workArea,
             Plate = Plate,
             PlateNumber = PlateNumber,
@@ -474,7 +476,7 @@ internal class DefaultPlateFiller : PlateFillerBase
                         {
                             Phase = context.WinnerPhase,
                             PlateNumber = PlateNumber,
-                            Parts = context.CurrentBest,
+                            Parts = context.ToOriginalFrame(context.CurrentBest),
                             WorkArea = context.WorkArea,
                             Description = BuildProgressSummary(),
                             IsOverallBest = true,