LinwoodDev/Butterfly ? reverse-engineered prompt

Build me a clean, minimal note taking app with an endless canvas where I can mix handwriting, typed text, Markdown, shapes, lines, images, and imported PDFs or SVGs.

I want it to feel good for sketching ideas, class notes, planning, whiteboarding, and simple presentations, with tools for pen drawing, eraser, moving and resizing items, layers, pages, folders, and reusable templates or palettes. It should work offline first, save files locally, and let me export notes as PDF, SVG, images, or a portable project file.

Please make it work well on web, desktop, and mobile, with a simple, polished UI that stays fast and editable as the page gets bigger. If you need current details for how the cross platform setup should be done, look up the latest docs online and follow the project style from the repo.