refactor(launcher): reorganize into responsibility folders

Co-authored-by: Cursor <cursoragent@cursor.com>

LanMountainDesktop.Launcher/Infrastructure/ThemeService.cs

@@ -0,0 +1,68 @@
+using Avalonia;
+using Avalonia.Styling;
+using FluentAvalonia.Styling;
+
+namespace LanMountainDesktop.Launcher.Infrastructure;
+
+/// <summary>
+/// 主题服务，管理启动器的主题设置
+/// </summary>
+public static class ThemeService
+{
+    private static ThemeVariant _currentTheme = ThemeVariant.Light;
+    private static string _accentColor = "#0078D4";
+
+    /// <summary>
+    /// 获取当前主题
+    /// </summary>
+    public static ThemeVariant CurrentTheme => _currentTheme;
+
+    /// <summary>
+    /// 获取当前主题色
+    /// </summary>
+    public static string AccentColor => _accentColor;
+
+    /// <summary>
+    /// 应用主题设置
+    /// </summary>
+    public static void ApplyTheme(ThemeMode mode, string accentColor)
+    {
+        _currentTheme = mode switch
+        {
+            ThemeMode.Dark => ThemeVariant.Dark,
+            _ => ThemeVariant.Light
+        };
+        _accentColor = accentColor;
+
+        // 应用到当前应用程序
+        if (Application.Current is { } app)
+        {
+            app.RequestedThemeVariant = _currentTheme;
+        }
+    }
+
+    /// <summary>
+    /// 应用浅色主题
+    /// </summary>
+    public static void ApplyLightTheme(string accentColor)
+    {
+        ApplyTheme(ThemeMode.Light, accentColor);
+    }
+
+    /// <summary>
+    /// 应用深色主题
+    /// </summary>
+    public static void ApplyDarkTheme(string accentColor)
+    {
+        ApplyTheme(ThemeMode.Dark, accentColor);
+    }
+}
+
+/// <summary>
+/// 主题模式
+/// </summary>
+public enum ThemeMode
+{
+    Light,
+    Dark
+}