feat(ui): show each drawing's count on the current plate

The drawing list only showed nest-wide totals, so seeing how many of a
drawing a layout holds meant counting parts by eye. Prefix the nested
line with the current plate's count, e.g. "[78] 144 of 1 nested".

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

OpenNest/Controls/DrawingListBox.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Drawing;
+using System.Linq;
 using System.Windows.Forms;
 using Size = System.Drawing.Size;
 
@@ -108,6 +109,12 @@ namespace OpenNest.Controls
 
         public bool HideQuantity { get; set; }
 
+        /// <summary>
+        /// The plate shown beside the list; each drawing's count on it prefixes the nested
+        /// quantity. Null omits the count.
+        /// </summary>
+        public Plate Plate { get; set; }
+
         protected override void OnDrawItem(DrawItemEventArgs e)
         {
             if (e.Index >= Items.Count || e.Index <= -1)
@@ -198,6 +205,11 @@ namespace OpenNest.Controls
                     dwg.Quantity.Nested,
                     dwg.Quantity.Required
                 );
+                var onPlate = Plate?.Parts.Count(part => part.BaseDrawing == dwg) ?? 0;
+
+                if (onPlate > 0)
+                    text1 = $"[{onPlate}] {text1}";
+
                 pt.Y += 22;
                 e.Graphics.DrawString(text1, Font, detailBrush, pt);
                 pt.Y += 18;

OpenNest/Forms/EditNestForm.cs

@@ -502,6 +502,7 @@ namespace OpenNest.Forms
 
             Text = Nest.Name;
             drawingListBox1.Units = Nest.Units;
+            drawingListBox1.Plate = PlateManager.CurrentPlate;
         }
 
         private void UnbindNest()
@@ -1627,6 +1628,8 @@ namespace OpenNest.Forms
         {
             PlateView.Plate = PlateManager.CurrentPlate;
             PlateView.ZoomToFit();
+            drawingListBox1.Plate = PlateManager.CurrentPlate;
+            drawingListBox1.Invalidate();
             SelectCurrentPlateInList();
             UpdatePlateHeader();
             UpdateRemovePlateButton();