refactor: move GpuEvaluatorFactory to OpenNest.Gpu project

GPU factory logic belongs with the GPU implementation, not the UI.
Changed from internal to public and updated namespace to OpenNest.Gpu.

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

OpenNest/Actions/ActionClone.cs

@@ -4,6 +4,7 @@ using System.Linq;
 using System.Windows.Forms;
 using OpenNest.Controls;
 using OpenNest.Geometry;
+using OpenNest.Gpu;
 
 namespace OpenNest.Actions
 {

OpenNest/Actions/ActionFillArea.cs

@@ -1,6 +1,7 @@
 using System.ComponentModel;
 using System.Windows.Forms;
 using OpenNest.Controls;
+using OpenNest.Gpu;
 
 namespace OpenNest.Actions
 {

OpenNest/Forms/MainForm.cs

@@ -6,6 +6,7 @@ using System.Reflection;
 using System.Windows.Forms;
 using OpenNest.Actions;
 using OpenNest.Collections;
+using OpenNest.Gpu;
 using OpenNest.Geometry;
 using OpenNest.IO;
 using OpenNest.Properties;

OpenNest/GpuEvaluatorFactory.cs

@@ -1,77 +0,0 @@
-using System;
-using System.Diagnostics;
-using ILGPU;
-using ILGPU.Runtime;
-using OpenNest.Engine.BestFit;
-using OpenNest.Gpu;
-
-namespace OpenNest
-{
-    internal static class GpuEvaluatorFactory
-    {
-        private static bool _probed;
-        private static bool _gpuAvailable;
-        private static string _deviceName;
-
-        public static bool GpuAvailable
-        {
-            get
-            {
-                if (!_probed) Probe();
-                return _gpuAvailable;
-            }
-        }
-
-        public static string DeviceName
-        {
-            get
-            {
-                if (!_probed) Probe();
-                return _deviceName ?? "None";
-            }
-        }
-
-        public static IPairEvaluator Create(Drawing drawing, double spacing)
-        {
-            if (!GpuAvailable)
-                return null;
-
-            try
-            {
-                return new GpuPairEvaluator(drawing, spacing);
-            }
-            catch (Exception ex)
-            {
-                Debug.WriteLine($"[GpuEvaluatorFactory] GPU evaluator failed: {ex.Message}");
-                return null;
-            }
-        }
-
-        private static void Probe()
-        {
-            _probed = true;
-
-            try
-            {
-                using var context = Context.CreateDefault();
-                foreach (var device in context.Devices)
-                {
-                    if (device.AcceleratorType == AcceleratorType.Cuda ||
-                        device.AcceleratorType == AcceleratorType.OpenCL)
-                    {
-                        _gpuAvailable = true;
-                        _deviceName = device.Name;
-                        Debug.WriteLine($"[GpuEvaluatorFactory] GPU found: {device.Name} ({device.AcceleratorType})");
-                        return;
-                    }
-                }
-
-                Debug.WriteLine("[GpuEvaluatorFactory] No GPU device found");
-            }
-            catch (Exception ex)
-            {
-                Debug.WriteLine($"[GpuEvaluatorFactory] GPU probe failed: {ex.Message}");
-            }
-        }
-    }
-}