fix: 修复返回引用类型导致的设置保存失败

DownKyi.Core/Settings/Models/WindowSettings.cs

@@ -6,4 +6,15 @@ public class WindowSettings
     public double Height { get; set; } = 750; // 默认高度
     public double X { get; set; } = double.NaN; // 默认位置未设置
     public double Y { get; set; } = double.NaN; // 默认位置未设置
+
+    public WindowSettings Clone()
+    {
+        return new WindowSettings
+        {
+            Width = Width,
+            Height = Height,
+            X = X,
+            Y = Y
+        };
+    }
 }

DownKyi/Views/MainWindow.axaml.cs

@@ -7,12 +7,12 @@ namespace DownKyi.Views;
 
 public partial class MainWindow : Window
 {
-    private readonly WindowSettings _windowSettings;
+    private WindowSettings _windowSettings;
 
     public MainWindow()
     {
         InitializeComponent();
-        _windowSettings = SettingsManager.GetInstance().GetWindowSettings();
+        _windowSettings = SettingsManager.GetInstance().GetWindowSettings().Clone();
         ApplyWindowSettings();
     }