Function proxy_args 

pub fn proxy_args(
    argv: &[String],
    config: &Config,
) -> Result<Vec<String>, String>

Build the argv for rtk proxy -- <argv>.

This one executes. It takes an already-split argument vector rather than a command string precisely so nothing here ever reaches a shell: the words the caller supplies are the words that are executed, and no quoting, globbing, pipeline or ; is interpreted along the way.