feat: add plate utilization to UI status bar

Display current plate utilization percentage in the status bar,
updating live when parts are added or removed.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

OpenNest/Forms/MainForm.Designer.cs

@@ -131,6 +131,7 @@
             plateIndexStatusLabel = new System.Windows.Forms.ToolStripStatusLabel();
             plateSizeStatusLabel = new System.Windows.Forms.ToolStripStatusLabel();
             plateQtyStatusLabel = new System.Windows.Forms.ToolStripStatusLabel();
+            plateUtilStatusLabel = new System.Windows.Forms.ToolStripStatusLabel();
             gpuStatusLabel = new System.Windows.Forms.ToolStripStatusLabel();
             selectionStatusLabel = new System.Windows.Forms.ToolStripStatusLabel();
             toolStrip1 = new System.Windows.Forms.ToolStrip();
@@ -829,7 +830,7 @@
             // 
             // statusStrip1
             // 
-            statusStrip1.Items.AddRange(new System.Windows.Forms.ToolStripItem[] { statusLabel1, locationStatusLabel, selectionStatusLabel, spacerLabel, plateIndexStatusLabel, plateSizeStatusLabel, plateQtyStatusLabel, gpuStatusLabel });
+            statusStrip1.Items.AddRange(new System.Windows.Forms.ToolStripItem[] { statusLabel1, locationStatusLabel, selectionStatusLabel, spacerLabel, plateIndexStatusLabel, plateSizeStatusLabel, plateQtyStatusLabel, plateUtilStatusLabel, gpuStatusLabel });
             statusStrip1.Location = new System.Drawing.Point(0, 630);
             statusStrip1.Name = "statusStrip1";
             statusStrip1.Padding = new System.Windows.Forms.Padding(1, 0, 16, 0);
@@ -889,7 +890,15 @@
             plateQtyStatusLabel.Padding = new System.Windows.Forms.Padding(5, 0, 5, 0);
             plateQtyStatusLabel.Size = new System.Drawing.Size(55, 19);
             plateQtyStatusLabel.Text = "Qty : 0";
-            // 
+            //
+            // plateUtilStatusLabel
+            //
+            plateUtilStatusLabel.BorderSides = System.Windows.Forms.ToolStripStatusLabelBorderSides.Left;
+            plateUtilStatusLabel.Name = "plateUtilStatusLabel";
+            plateUtilStatusLabel.Padding = new System.Windows.Forms.Padding(5, 0, 5, 0);
+            plateUtilStatusLabel.Size = new System.Drawing.Size(75, 19);
+            plateUtilStatusLabel.Text = "Util : 0.0%";
+            //
             // gpuStatusLabel
             // 
             gpuStatusLabel.BorderSides = System.Windows.Forms.ToolStripStatusLabelBorderSides.Left;
@@ -1128,6 +1137,7 @@
         private System.Windows.Forms.ToolStripSeparator toolStripMenuItem10;
         private System.Windows.Forms.ToolStripMenuItem mnuCloseAll;
         private System.Windows.Forms.ToolStripStatusLabel plateQtyStatusLabel;
+        private System.Windows.Forms.ToolStripStatusLabel plateUtilStatusLabel;
         private System.Windows.Forms.ToolStripMenuItem mnuFileExportAll;
         private System.Windows.Forms.ToolStripMenuItem openNestToolStripMenuItem;
         private System.Windows.Forms.ToolStripMenuItem pEPToolStripMenuItem;

OpenNest/Forms/MainForm.cs

@@ -204,6 +204,7 @@ namespace OpenNest.Forms
                 plateIndexStatusLabel.Text = string.Empty;
                 plateSizeStatusLabel.Text = string.Empty;
                 plateQtyStatusLabel.Text = string.Empty;
+                plateUtilStatusLabel.Text = string.Empty;
                 return;
             }
 
@@ -219,6 +220,10 @@ namespace OpenNest.Forms
             plateQtyStatusLabel.Text = string.Format(
                 "Qty: {0}",
                 activeForm.PlateView.Plate.Quantity);
+
+            plateUtilStatusLabel.Text = string.Format(
+                "Util: {0:P1}",
+                activeForm.PlateView.Plate.Utilization());
         }
 
         private void UpdateSelectionStatus()
@@ -342,6 +347,8 @@ namespace OpenNest.Forms
                 activeForm.PlateView.MouseClick -= PlateView_MouseClick;
                 activeForm.PlateView.StatusChanged -= PlateView_StatusChanged;
                 activeForm.PlateView.SelectionChanged -= PlateView_SelectionChanged;
+                activeForm.PlateView.PartAdded -= PlateView_PartAdded;
+                activeForm.PlateView.PartRemoved -= PlateView_PartRemoved;
             }
 
             // If nesting is in progress and the active form changed, cancel nesting
@@ -367,6 +374,8 @@ namespace OpenNest.Forms
             UpdateSelectionStatus();
             activeForm.PlateView.StatusChanged += PlateView_StatusChanged;
             activeForm.PlateView.SelectionChanged += PlateView_SelectionChanged;
+            activeForm.PlateView.PartAdded += PlateView_PartAdded;
+            activeForm.PlateView.PartRemoved += PlateView_PartRemoved;
             mnuViewDrawRapids.Checked = activeForm.PlateView.DrawRapid;
             mnuViewDrawBounds.Checked = activeForm.PlateView.DrawBounds;
             statusLabel1.Text = activeForm.PlateView.Status;
@@ -1215,6 +1224,9 @@ namespace OpenNest.Forms
 
         #region PlateView Events
 
+        private void PlateView_PartAdded(object sender, ItemAddedEventArgs<Part> e) => UpdatePlateStatus();
+        private void PlateView_PartRemoved(object sender, ItemRemovedEventArgs<Part> e) => UpdatePlateStatus();
+
         private void PlateView_MouseMove(object sender, MouseEventArgs e)
         {
             UpdateLocationStatus();