This means that anyone serving up the webapp to users as a service
(ie, without providing any git-annex binary at all to the user) still needs
to provide a link to the source code for it, including any modifications
they may make.
This may make git-annex be covered by the AGPL as a whole when it is built
with the webapp. If in doubt, you should ask a lawyer.
When git-annex is built with the webapp disabled, no AGPLed code is used.
Even building in the assistant does not pull in AGPLed code.