Follow-ups from the review of #414. The credential guard now checks each staged .npmrc rather than only the client one: the root and sas/ files are tracked policy as well, so a token pasted into either was equally one `git add -A` away. Verified by staging a token in sas/.npmrc - the hook exits 1. $RUNNER_TEMP/npmrc is removed at the end of each job that writes it, with `if: always()` so a failed job cleans up too. The root `install` script is gone: the root .npmrc sets ignore-scripts, so npm never ran it. CONTRIBUTING already spells out the per-project commands, and is now the single source. The release workflows build the published client from the same tree, so they run `check:archiver` like build.yaml does.