replit/prybar ? reverse-engineered prompt

Build me a small Go tool that acts like a universal front end for different language interpreters, so every language feels the same from the command line. I want to be able to run code, evaluate a single expression, run a file, or drop into an interactive REPL with a shared interface and simple prompts.

Please make it support the languages listed in the repo, and use the right backend for each one, with a sensible fallback when a language needs a small helper script instead of direct bindings. Keep it easy to build and test from the project root, and make sure the Docker and Nix flows still work so it can be packaged and distributed cleanly.

If you need to check current interpreter docs or install steps for any language, look them up online. After that, make sure the commands behave consistently across languages and the tests pass.