zhao-cli: a free, deterministic breaking-change gate for dbt

I kept hitting the same problem on almost every dbt project I worked on: a PR changes a column somewhere mid-DAG, and the only way to know what it actually breaks downstream is to either read the SQL by hand across every model that might reference it, or rebuild the whole project/downstream in CI and wait. Neither scales past a DAG of any real size. So over the last few weeks, after hours, I built zhao-cli to fix that for myself , and since it turned out to actually work, I'm putting it out the