jdx/mise ? reverse-engineered prompt

Build me a command-line tool that acts as a universal manager for my development environments. When I switch into a project's directory, I want it to automatically handle everything for me based on a simple config file in that folder.

It should be able to manage different versions of development tools, like Node, Python, or Go, making sure the correct version is active for each specific project. It should also handle environment variables, loading them when I cd into the directory, similar to how direnv works.

Finally, I want it to be a simple task runner. I'd like to define common project commands like build, test, or deploy right in that same configuration file, so anyone on the team can run them with a simple command like mise run deploy. It needs to be a single, fast binary that can replace a bunch of other tools.