can now export to #OpenTimelineIO format from #miruVideoEditor and open it in #kdenlive. Missing metadata like resolution, clip volume and effects, but still pretty neat

Currently working on a feature to preview changes in the #MiruVideoEditor without syncing so that:

- users are less likely to get confused by clips flashing between their and someone else's changes (in theory)
- fewer ephemeral #CRDT updates are sent between users
- we can more easily have an [Esc] key to cancel current drag/resize, or close a dialog without applying changes
- we can use the same preview system with a lightweight real-time API for live changes from other clients