zuohuaijun/Admin.NET — reverse-engineered prompt

Build me a ready to use admin system for a small or medium business, with a .NET backend and a Vue based web dashboard. I want it to feel like a general purpose management platform out of the box, with login, role and permission control, users, departments, jobs, menus, dictionaries, system settings, dashboards, logs, online users, announcements, file upload and download, scheduled jobs, and API docs. It should support multi tenant use, caching, validation, auth, real time notifications, and common database setups, with seed data so it can start quickly.

Please keep the code clean and easy to extend, because I may add my own business modules later as a separate application layer instead of hacking the core. If possible, include practical extras like import and export, code generation, a drag and drop form builder, and support for email or SMS and OAuth style login. Make it run on Windows or Linux, and look up the current project docs or demo online if you need details.