tl;dr: A developer built "riddle," a Rust app that turns a reMarkable Paper Pro (in developer mode) into Tom Riddle's diary: handwritten ink fades from the page, gets sent as a PNG to a vision LLM (any OpenAI-compatible API or a local `pi` backend), and the streamed reply is rendered back in flowing Dancing Script handwriting. It achieves ~1s to first ink by taking over the vendor e-ink engine directly via a shim over `libqsgepaper.so`, bypassing the normal UI for minimal latency.