Switch away from `morphdom`?

Why? Performance issues: https://github.com/srid/emanote/discussions/566 https://github.com/srid/emanote/issues/411

What about `idiomorph` (from the htmx people)?

- https://www.reddit.com/r/htmx/comments/xcj6zd/a_new_swapping_mechanism_for_htmx_idiomorph/
- https://github.com/bigskysoftware/idiomorph/