refactor(设置): 重构设置窗口为独立窗口并移除旧设置面板

移除旧的内置设置面板及相关代码，将设置功能迁移至独立的设置窗口
优化设置窗口的主题同步功能，调整自动化页面布局

Ink Canvas/Windows/SettingsViews/SettingsWindow.xaml.cs

@@ -33,6 +33,8 @@ namespace Ink_Canvas.Windows.SettingsViews
         {
             InitializeComponent();
 
+            ApplyCurrentTheme();
+
             // 初始化内置页面映射
             _pageTypes = new Dictionary<string, Type>
             {
@@ -124,6 +126,27 @@ namespace Ink_Canvas.Windows.SettingsViews
             };
         }
 
+        public void RefreshTheme()
+        {
+            ApplyCurrentTheme();
+        }
+
+        private void ApplyCurrentTheme()
+        {
+            try
+            {
+                int themeIndex = Helpers.SettingsManager.Settings.Appearance.Theme;
+                var elementTheme = themeIndex switch
+                {
+                    0 => iNKORE.UI.WPF.Modern.ElementTheme.Light,
+                    1 => iNKORE.UI.WPF.Modern.ElementTheme.Dark,
+                    _ => iNKORE.UI.WPF.Modern.ElementTheme.Default,
+                };
+                iNKORE.UI.WPF.Modern.ThemeManager.SetRequestedTheme(this, elementTheme);
+            }
+            catch { }
+        }
+
         #region 修复触摸屏鼠标指针消失问题
 
         [System.Runtime.InteropServices.DllImport("user32.dll")]