Splendid work, thanks for sharing!
I like to bundle/minify the production code for the same your reasons.
I've checked out your code from the repo and I noticed that the build directory cannot be renamed.
# works
$ node build
# attempt 1 - does not work
$ mv build my-app
$ node my-app
# attempt 2 - does not work
$ cd build
$ node .
Any ideas to build the application, than move artifacts and run without any prefix ?