How can I save a web page with external resources like browsers' "save complete web page" but from command line or with node?
That is executing command /uri/of/page.html saves all js and css files referenced in page.html.
You can use wget and its recursive download ability.
http://www.gnu.org/software/wget/manual/wget.html#Recursive-Download
$ wget -r
or
$ wget --page-requisites