erickong/penecho ? reverse-engineered prompt

Build me a local app called PenEcho that gives me a shared whiteboard for thinking with AI instead of just chatting.

I want to be able to draw by hand, write equations, sketch diagrams, and place ideas around the canvas so the AI can understand the full visual context. The app should have a simple canvas UI with a toolbar, an Auto AI mode, and a way to choose the reasoning level for each request. It should work with either Claude, Codex, or a generic API based setup, and there should be a quick interactive setup screen to save my model and connection settings.

Please make it feel polished and easy to run from the command line, with a local config file, a clear start command, and sensible defaults. If you need to check current docs or model details online, do that. I’d also like the app to save requests for debugging if that’s already part of the design, and to keep the experience fast when the server starts.