4sou9/Steam_Idle_Picker ? reverse-engineered prompt

Build me a Windows desktop app that lets me keep selected Steam games showing as Playing at the same time.

I want it to launch, find my Steam library after I hit refresh, and show a clean list of games where I can check the ones I want to idle. The checked games should stay pinned at the top, and I should be able to start idling them all with one play button, then stop everything with the same button when it changes to stop.

Please cap it at 32 games, and show a footer count like how many are currently being idled out of the max. I also want the ability to uncheck a single game to stop just that one. If possible, make it feel polished with a custom title bar, dark and light theme support based on Windows, and English or Japanese text depending on the system language.

Use a modern desktop setup and make sure it works on Windows 10 and 11 with Steam already running.