消息提示帮助类（MsgBox）

避免到处写 MessageBox.Show，统一风格和日志记录：

public static class MsgBox
{
    public static void Info(string text, string caption = "提示")
    {
        MessageBox.Show(text, caption, MessageBoxButtons.OK, MessageBoxIcon.Information);
    }

    public static void Warn(string text, string caption = "警告")
    {
        MessageBox.Show(text, caption, MessageBoxButtons.OK, MessageBoxIcon.Warning);
    }

    public static void Error(string text, string caption = "错误")
    {
        MessageBox.Show(text, caption, MessageBoxButtons.OK, MessageBoxIcon.Error);
    }

    public static bool Confirm(string text, string caption = "确认")
    {
        return MessageBox.Show(text, caption, MessageBoxButtons.YesNo, MessageBoxIcon.Question) == DialogResult.Yes;
    }
}