Assets directories need to be writable by the web server

[sebbASF]

If Wunderbar does not find an asset with the expected name and size, it tries to install a copy from the embedded vendor files.

This requires write access to (parts of) the directory structure by the running webserver, which is not normally recommended.

If the resources are to be bundled with Wunderbar, a workround might be to have a setup script that can be used to populate an assets directory. There would still be a potential issue when Wunderbar resources are updated, unless the Asset code is also changed so it does not try to replace any files that are not the expected size.

It would probably be useful to keep the existing search logic, so users can install the files centrally or locally to each app.