nodaysidle/nodaysidle-cascade-v3 ? reverse-engineered prompt

Build me a desktop app for macOS that takes one rough software idea and turns it into five clean markdown files that I can hand to an AI coding agent.

I want the app to help me describe the product once, then produce PRD, ARD, TRD, TASKS, and AGENTS docs that all match each other and are ready to export. It should feel local first, keep my provider key only in memory, and not send anything anywhere except the one model request it needs. The app should show me the generated preview before export, let me pick an output folder, and make sure the exported files are exactly the same as what I saw in the preview.

Please include a simple intake flow, a few preset options for different app types, and clear validation so it can warn me if my idea is too vague or conflicts with the chosen preset. If you need to look up current docs online for Tauri or anything else, go ahead.