gridstack/gridstack.js — reverse-engineered prompt

Build me a reusable TypeScript library for making interactive dashboard layouts in the browser. I want people to be able to create a dashboard area, add cards or widgets to it, then drag them around and resize them like a modern admin dashboard.

It should work well on desktop and touch devices, support multiple columns, and adjust nicely when the screen size changes. Users should be able to create widgets from normal HTML or add them through a simple API, and also load a layout from saved position data.

Please include clean styling, sensible defaults, and demos that show the basic use cases, like adding widgets, resizing them, changing columns, and loading a dashboard from data. It should not depend on jQuery or heavy outside libraries. If it makes sense, include simple examples or wrappers for React, Angular, and Vue so people can use it in those apps too. Look up current browser and framework docs if you need to.