7rebux/League-Tools ? reverse-engineered prompt

Build me a cross platform desktop app for League of Legends players that lets them customize their League client profile and related status settings in one place.

I want an easy to use UI where someone can change their profile icon to any icon, set a custom profile background from a splash art, extend their status text beyond the normal limit, appear offline or switch availability, clear challenge tokens, reuse a challenge token, and show a custom rank in ranked modes and challenges.

It should feel like a simple companion app with a clean interface, work on desktop, and include a mock mode so the UI can still be explored without a running League client. Make it look polished, handle connecting to the client gracefully, and keep the changes applied locally in the app when in mock mode. If you need to, look up the current League client API docs online first.