PolicyKit and various system scripts are undocumented

[ar-lex]

I haven't found the information on the PolicyKit helpers specific to SteamOS and corresponding system scripts, particularly

• /usr/bin/steamos-polkit-helpers/steamos-update that is a part steamos-customization. It invokes /usr/bin/steamos-update for which I haven't found the source package name. All I know is that this script runs when the user clicks Check for updates button in Steam Deck UI.
• /usr/bin/steamos-session-select that makes changes to SDDM configuration and restarts it after switching to desktop mode from Steam Deck UI. I also haven't found the source package for this script.

If anyone knows the packages to which these scripts belong or any information on it's mechanisms, please let me know. I'd like to contribute to documenting this part of SteamOS.

[ar-lex]

I've found out that both steamos-update and steamos-session-select scripts belong to jupiter-legacy-support binary package but not the source. Weird.