Spotifyd/spotifyd ? reverse-engineered prompt

Build me a lightweight open source Spotify client that runs in the background on UNIX systems as a daemon. I want it to stream music like the normal Spotify app, but without a full desktop interface, and it should show up in the official Spotify app as a Spotify Connect device so I can control playback from my phone or laptop.

Assume the user has Spotify Premium, and make that clear in the setup notes. Keep it focused on being reliable, small, and easy to run on Linux and similar systems. It should have a simple config file for login, device name, audio output, and any basic options a normal user would expect. Include clear install and configuration instructions, plus examples for starting it as a background service.

Use Rust for the main implementation. Look up current docs online if you need to, especially around Spotify Connect behavior and platform setup.