cinnyapp/cinny ? reverse-engineered prompt

Build me a clean web Matrix chat app like Cinny. I want it to feel simple, elegant, modern, and reasonably secure, not cluttered or overly technical. People should be able to sign in with their Matrix account, get into their rooms quickly, browse public or explore spaces, and chat in a nice instant messaging interface that feels easy on the eyes.

Please make it something I can self host without much pain. I want a simple config for default homeservers and explore pages, and it should work both with normal routes and with a hash route fallback for basic hosting setups. It should run locally for development, build into static files for deployment, and also have a Docker option that serves the app in the browser.

Use the current setup that makes sense for this repo, and make sure the app is actually usable end to end. If you need details, look up the current Matrix docs and common self hosting examples online.