How to organize coupled online editor repository & resources repository for it?

I have setup CI for building and publishing online editor (js) onto gitlab pages. Considering that gitlab isn’t providing CORS headers I have to manually put resources from another repository to the public directory of editor’s one and commit all of them. It feels like overhead and depreciates advantages of CI process.
Can you advice smart solution that implements such options:

  • when I commit code update to the editor’s repository – CI configuration rebuilds and publish it, all old resources are kept intact and still accessible;
  • when artist commits update of the resources – somehow CI configuration updates public directory of online editor, but editor must not be rebuilded;

Thus there will be no need to push updated resources manually and rebuild editor every time. Probably this problem can be solved by different hooks and submodules?