Artifact in this context is whatever is produced by build process. That is common convention in CI/CD context. And the base definition for "artifact" is very wide: anything artificial, as in not natural but made by humans.
There is a bit of manual tweaking required in LaTeX that I haven't figured out how to automate yet. It's mainly related to chapter endings: if there are only 2 or 3 lines on the last page, I can subtly tighten the tracking from a paragraph on the second to last page and eliminate an almost-empty page. Also, I have PNG maps that currently need some one-off LaTeX directives to lay them out how I want. I could probably embed some properties in the ODT image, but that seems kind of janky. If I needed to regenerate from the ODT source, I use a Git three-way merge to update it (also janky, but it's expedient).