h2oai/wave ? reverse-engineered prompt

Build me a small app using H2O Wave that shows how to make a realtime browser dashboard in Python, with an option to use R too if that fits. I want a clean, modern dashboard that can display live data from a few sources, update instantly without page reloads, and look good on desktop and mobile. Please include a handful of common dashboard widgets like charts, tables, filters, cards, and a simple theme switcher so I can see what Wave can do.

I do not want to write any HTML, JavaScript, or CSS by hand, just the app code and whatever setup is needed to run it. Make it easy to launch locally, include a few example screens or demo data, and structure it so I can extend it later with my own realtime data. If you need to check current Wave docs online, go ahead and do that.