Append RealChild (real tokio::process::Child wrapper) and spawn_with_logs
to child.rs. Uses nix::unistd::setpgid via tokio's re-exported pre_exec
to create an own process group, and fires per-stream log pump tasks that
drain stdout/stderr into the provided LogSink. terminate/kill signal the
whole process group via kill(-pgid, SIG*).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>