"I will work on your project".
Hello
Nice to meet you.
I have read your descriptions carefully.
I have ever done such your project.
Then I used ElectronJS, webRTC for screen sharing.
But in your descriptions, you wanted c# or c++.
I have rich experiences in c# and c++.
To do your project, backend must be prepared(for Login, signup etc)
So I think it is better to use ElectronJS than c#/c++.
This is my think.
Anyway, I wish discuss about your requirement correctly.
Kind regards.
Vu D