So if it needs to work offline, but it syncs with a server, then you use both? (And the schema becomes some kind of lowest common denominator?)
yeah essentially, see electricsql
though they also have "pglite" running in wasm.
same concept though, sync slices to an embedded db.
I would probably do an event-source architecture, where you record events on the client and then push them to the server when you're reconnected. It has a lot of benefits, for instance, trivial auditing and free serialization.