Opening the book…
Half of all "the build broke overnight" reports are a teammate on a different Node major or a pac CLI that auto-updated. The code did not change; the toolchain did.
Record the known-good pair (e.g. Node 18 LTS, pac 1.32) at the top of the README. First move when a build fails on one machine but not another: run the version-check card and compare against the README.