signalapp/signal-desktop ? reverse-engineered prompt

Build me the desktop Signal app from this repo so it feels like a real private messenger people can use every day. I want it to pair with the Signal app on Android or iPhone, then let someone read and send messages from their computer on Windows, macOS, and Linux. Please make the main experience solid, with linking, chat list, conversation view, message sending, notifications, media and sticker support where the project already expects it, and the usual screens like loading, permissions, about, and debug log.

Use the code that is already here instead of reinventing things, and get it into a state where I can run it locally and see the full desktop flow working. If there are missing pieces or setup steps, handle them in the most sensible way and leave clear notes. You can look up current docs online if you need to.