These icons are from the Breeze icon theme, licensed under the GPLv3.
https://github.com/KDE/breeze-icons

The onion-on and onion-off icons are from Krita, also licensed under the GPLv3.
https://krita.org/

The Discord icon is adapted from Font Awesome Free 6.4.0 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License) Copyright 2023 Fonticons, Inc.
