I think, traditionally, front-end has meant html/css/js. With the promise of node, however, and other blending of server and client side technologies, that may not necessarily be the case. Also, beware people who seek to clearly delineate between titles. no jobs are so clearly defined in reality.

If I were to write a book on front end engineering (in addition to the items already mentioned), I would make sure to include the science of UX. Specifically, the analyses done by Jakob Nielson at UseIt.com. I would discuss some psychology, so that your interface and your site objective are aligned. I would also have them learn some copywriting skills (the concepts of landing pages should be well covered).

Also: analytics, social media (so much of it is done through widgets now), user testing.