refactor: replace NestPhase switch statements with attribute-based extensions

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

OpenNest/Controls/PhaseStepperControl.cs

@@ -59,16 +59,6 @@ namespace OpenNest.Controls
             }
         }
 
-        private static string GetDisplayName(NestPhase phase)
-        {
-            switch (phase)
-            {
-                case NestPhase.RectBestFit: return "BestFit";
-                case NestPhase.Nfp: return "NFP";
-                default: return phase.ToString();
-            }
-        }
-
         protected override void OnPaint(PaintEventArgs e)
         {
             base.OnPaint(e);
@@ -134,7 +124,7 @@ namespace OpenNest.Controls
                 }
 
                 // Label
-                var label = GetDisplayName(phase);
+                var label = phase.ShortName();
                 var font = isVisited || isActive ? BoldLabelFont : LabelFont;
                 var brush = isVisited || isActive ? activeTextBrush : pendingTextBrush;
                 var labelSize = g.MeasureString(label, font);

OpenNest/Forms/NestProgressForm.cs

@@ -73,7 +73,7 @@ namespace OpenNest.Forms
 
             descriptionValue.Text = !string.IsNullOrEmpty(progress.Description)
                 ? progress.Description
-                : FormatPhase(progress.Phase);
+                : progress.Phase.DisplayName();
         }
 
         public void ShowCompleted()
@@ -196,18 +196,5 @@ namespace OpenNest.Forms
                 return DensityMidColor;
             return DensityHighColor;
         }
-
-        private static string FormatPhase(NestPhase phase)
-        {
-            switch (phase)
-            {
-                case NestPhase.Linear: return "Trying rotations...";
-                case NestPhase.RectBestFit: return "Trying best fit...";
-                case NestPhase.Pairs: return "Trying pairs...";
-                case NestPhase.Extents: return "Trying extents...";
-                case NestPhase.Nfp: return "Trying NFP...";
-                default: return phase.ToString();
-            }
-        }
     }
 }