sparkjsdev/spark ? reverse-engineered prompt

Build me a web library and demo site for rendering 3D Gaussian splats in the browser with THREE.js.

I want it to load splat models from common formats like PLY, SPZ, SPLAT, KSPLAT, and SOG, then let me place them in a normal THREE.js scene alongside regular meshes. It should be fast, work well on phones and other low powered devices, and support multiple splat objects with correct sorting. I also want basic editing features like moving and rotating splats, changing their color, displacement, and simple animation support.

Please include a few polished examples I can run locally, plus clear docs and a simple build flow for the browser version. If there’s any recent setup detail that depends on current docs or best practice, look it up online as needed.