In the case of Wt, the JavaScript would not be considered the source code.
Yeah this is a big gray area, because in this case the javascript is the build artifact. It's the "compiled" version on the code.
I'd love to hear a lawyer weigh in on this.
It's not a grey area at all. The GPL clearly defines source code, and Javascript build artifacts ain't it.
Sort of, but the question is whether you're producing and distributing a derived work, and I'd say that is the case, even if the parts you're distributing aren't the "important" ones.