pub fn branch_base(branch: &str) -> Option<String>Expand description
Read the recorded base branch for a branch (branch.<name>.gwBase).
gw new --stack records the parent here so the workflow knows a branch is
stacked before its PR exists; once a PR exists, GitHub’s base is the source
of truth instead. Returns None when unset (the branch targets the default
branch). It is a local config read — no network.