gpui-pre-web 0.3.0

Zed's `gpui_web` crate (gpui-pre snapshot of zed@b1a7ef0)
Documentation

GPUI's browser platform uses one document-owned canvas and supports one top-level window. Browser WebGPU is preferred by default, with an automatic WebGL2 fallback. Applications can force either backend with [WebBackendPreference]. Opening a second top-level window, or reopening one after it closes, returns [WebWindowError].