Your app might not need it but if you want partial replication or relational querying in addition to offline-first syncing then check out https://github.com/aspen-cloud/triplit (disclaimer: I'm working on this)
I think our goals are pretty similar but Triplit offers more flexible storage options (Durable Objects, IndexedDB, SQLite), deeper Typescript integration, and is probably a good deal simpler to operate--we are closer to Firebase/Firestore in that regard. ElectricSQL instead builds on the robustness of Postgres and SQLite.