terrarium-sh/terrarium ? reverse-engineered prompt

Build me a simple tool that lets me run a coding agent or shell session inside a lightweight virtual machine, instead of directly on my laptop.

I want to point it at a project folder, give it a small config file, and then create a box where that folder is mounted in, with optional read only access and a network allowlist. It should let me install a few packages on first setup, keep files and tools around between restarts, and let me jump back into the same box later, run single commands, stop it, or delete it.

It should work nicely for local development, be safe by default, and make it easy to try untrusted scripts or builds without exposing the whole host. If you need to look up current docs online while building it, go ahead.