how to protect PC against supply chain attacks?

Stack Overflow is specifically for programming questions; also see the help center for the kinds of questions that are allowed here. If you're developing a sandboxing tool, it would help to edit your question to include much more technical detail and a specific code example. As you've written it, this sounds like more of a general-computing or system-administration question, though, which would be better fit for a site like Super User or Server Fault.

Not developing a tool, but trying to set up a system using existing tooling to loosely accomplish the set requirements. First tried at unix stackexchange, but it was closed as being too unfocused and open-ended. Suspect super-user SE ends up being the same.