Function run_supervisor 

pub fn run_supervisor(
    ctx: &Context,
    reloader_name: &str,
    logs_dir: &str,
    proc_context: &str,
) -> Result<()>

Port of editmodeprocesssupervisor.run: loads the configuration, resolves the edit-mode processes configured for reloader_name that run in proc_context, and supervises them.

Deviation from Go: actual process supervision (restart-on-failure via ShinyTrinkets/overseer) has no Rust equivalent in this worktree yet, so this port covers every step up to (and including) the port conflict/invalid-command checks superviseAll performs before handing off to overseer.NewOverseer() – exactly the paths every non- integration Go test in this package exercises. If processes are actually selected to run, this returns an explicit error rather than silently doing nothing or pretending to supervise.