feat: show hover tooltip only after 1000ms of mouse stillness

Add a hoverTimer that restarts on each mouse move over a part.
Tooltip only renders after the timer fires, hiding while the
cursor is in motion.

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

OpenNest/Controls/PlateView.cs

@@ -36,6 +36,8 @@ namespace OpenNest.Controls
         private PlateRenderer renderer;
         private LayoutPart hoveredPart;
         private Point hoverPoint;
+        private bool showTooltip;
+        private Timer hoverTimer;
 
         public Box ActiveWorkArea
         {
@@ -99,6 +101,9 @@ namespace OpenNest.Controls
             };
             redrawTimer.Elapsed += redrawTimer_Elapsed;
 
+            hoverTimer = new Timer() { AutoReset = false, Interval = 1000 };
+            hoverTimer.Elapsed += (s, _) => { showTooltip = true; Invalidate(); };
+
             SetStyle(
                 ControlStyles.AllPaintingInWmPaint |
                 ControlStyles.OptimizedDoubleBuffer |
@@ -369,12 +374,22 @@ namespace OpenNest.Controls
                 if (hoveredPart != null)
                 {
                     hoverPoint = e.Location;
+                    showTooltip = false;
+                    hoverTimer.Stop();
+                    hoverTimer.Start();
                     Invalidate();
                 }
+                else
+                {
+                    hoverTimer.Stop();
+                    showTooltip = false;
+                }
             }
             else if (hoveredPart != null)
             {
                 hoveredPart = null;
+                hoverTimer.Stop();
+                showTooltip = false;
                 Invalidate();
             }
 
@@ -487,7 +502,7 @@ namespace OpenNest.Controls
 
             base.OnPaint(e);
 
-            if (hoveredPart != null)
+            if (hoveredPart != null && showTooltip)
             {
                 e.Graphics.ResetTransform();
                 var text = hoveredPart.BasePart.BaseDrawing.Name;