wtf is decky-wall?

Decky.wall is a plugin for the Steam Deck and similar handheld gaming devices that lets you show a live, animated Wallpaper Engine wallpaper behind the Steam Game Mode home screen, which is the gamepad-style interface you see behind your list of games. Other tools that add live wallpapers to a Steam Deck only work on the desktop side of the device, while this plugin specifically targets the actual gaming interface itself. It works with Wallpaper Engine content you already own through Steam, and it does not include any wallpapers of its own. Video wallpapers are reliably supported, web-based wallpapers work partially, and interactive scene wallpapers are not supported at all. The plugin requires Decky Loader, a separate tool that lets custom plugins run on the Steam Deck's Game Mode, and it only works on Linux-based systems like SteamOS or Bazzite, not on Windows. Setting it up involves two parts. First you install the plugin itself through Decky Loader while in Game Mode. Then, from Desktop mode, you use a separate browser-based tool, which must be Chrome, Edge, Brave, or Vivaldi since Firefox lacks a needed browser feature, to pick a wallpaper from your Wallpaper Engine library and prepare it for use in the plugin. Once that is done, switching back to Game Mode shows the wallpaper playing behind your games. Once installed, wallpapers can be switched without leaving Game Mode using a thumbnail picker in the Quick Access Menu, and different wallpapers can be assigned per game. Settings like brightness, position, and zoom can be adjusted from the same menu, and all preferences are saved on the device so they survive a restart. The project is open source under the MIT license and was built and tested on a ROG Xbox Ally X, with community confirmation that it also works on a Steam Deck OLED.