Feature: analytics插件数据登录后查看

公网部署的Koishi面板安装login/auth插件后可以保护插件配置等不被修改。但启用analytics插件后，插件在主页展示的统计信息却依然是公开的，任何人访问面板地址均可看到这些统计数据，包括使用koishi的群名、群号、私聊用户id等，是否可以设置让这些数据登录后才可查看（或可以设置指定对应的权限等级范围），保护这些隐私数据呢？

Start by locating the analytics plugin's homepage data and the existing login/auth integration in the WebUI. The work is done when analytics data is hidden from unauthenticated visitors and access can be restricted by a configured permission level, as requested.

Written by the indexing model from the issue text.