Start of a sandbox for GrapeJS
Remains of the sandboxed CKEditor - will be removed, but the version here may be useful for another editor that is prone to XSS (like Summernote).
WiP on selectable mosaico templates. TODO: Make files always point to trusted URL, such that we don't have to rebase them. They are public anyway. The same goes for mosaico endpoints: /mosaico/templates and /mosaico/img
Transition to SPA-style client Basis for Mosaico template editor
