Bundle UI as offline (web) app

[Frando]

It would be nice if the web app was usable when offline.

Options:

• "Progressive web app" with a Service Worker that caches the web page. You'd have to open the web app once, and then when offline if you'd open the same URL it would just work on modern browser.
• Static HTML export. Download a single HTML file, save it, and double-click to open it in your browser
• For mobile: Minimal app shell that just serves the static html export and/or PWA
• For desktop: A web view shell as a static small rust binary, e.g. with webview

I think for all three ways there's lots of docs and guides around.