I don't think Calva is very common is those setups. Probably Cursive is more common, since it runs in IntelliJ.

If Calva is used to start the REPL it will start it with whatever environment that VS Code has (as reported by the env command in an integrated terminal). In addition to this you can provide extra environment using the calva.jackInEnv setting. However, for classpath things deps.edn seem to be the tool to use, since it is designed for that.