Nozbe/WatermelonDB ? reverse-engineered prompt

Build me a fast, reactive database library for React and React Native apps that can handle lots of records without making the app feel slow.

I want it to store data locally with SQLite, work offline, and automatically update the UI when records change so lists, counters, and detail views stay in sync without me wiring everything by hand. It should support simple models and relationships like posts and comments, and make it easy to query data lazily so nothing heavy loads until it is actually needed.

Please make it work across mobile and web where possible, with a clean developer experience, good docs, and a small example app that shows how to define models and connect them to components. If there are setup details or current best practices I should follow, look up the latest docs online and use those.