So Aurora (https://github.com/element-hq/aurora) is a proof-of-concept we put together of rust-sdk on Web, using the new MVVM components from Element Web. However, the plan is likely not to actually switch base to Aurora, but instead migrate SDK within the existing app codebase eventually. (We might end up using Aurora for other purposes though). Either way, the ground work is the same: to split up the current app into MVVM components which can run on either js-sdk or rust-sdk.