You indeed seems to have dificult to port actual javascript code to Safari or a desktop Mac application. Therefore, why not consider implementing Passbolt in a native or cross-platform framework that allows the use of native features?
Yes this would initially require a significant overhaul, in the long run, but you would have access to all the features platform specific.
This could truly be a game changer for the future.
Maybe Passbolt should be aiming multiple languages at the same time?