I agree on the "just work" principle, but stuff like "docker compose" is easy enough to use, and "standard enough". Typing "docker compose up -d" once isn't that much effort. And make sure the connection string is configurable through an environment variable so people can use $something_else if they really want/need to.

Practicality beats purity, and all of that. Especially when it saves quite of complexity in the code itself – new contributors are going to struggle with that, too.

In short, the setup doesn't need to be manual.