chore: Add ujust install-gamemode-video to desktop, usable in Big Picture mode

system_files/desktop/shared/usr/share/ublue-os/firstboot/yafti.yml

@@ -22,6 +22,11 @@ screens:
           default: true
           packages:
           - Set input group: sudo -A ujust add-user-to-input-group
+        Install Game Mode Startup Video:
+          description: Adds a Bazzite themed startup video for Steam's game mode.
+          default: true
+          packages:
+          - Install Video: ujust install-gamemode-video
         Fix Steam Download Speed:
           description: Adds a config file that fixes download speed under Steam for Linux.
           default: true

system_files/desktop/shared/usr/share/ublue-os/just/80-bazzite.just

@@ -21,6 +21,12 @@ restore-original-terminal:
         sed -i '/NoDisplay=true/d' $HOME/.local/share/applications/org.kde.konsole.desktop
     fi
 
+# Install Bazzite's Steam Game Mode Startup Video
+install-gamemode-video:
+    mkdir -p $HOME/.local/share/Steam/config/uioverrides/movies
+    rm -f $HOME/.local/share/Steam/config/uioverrides/movies/deck_startup.webm
+    ln -s /usr/share/ublue-os/bazzite/bazzite.webm $HOME/.local/share/Steam/config/uioverrides/movies/deck_startup.webm
+
 # Remove all waydroid-related files in your user folders
 reset-waydroid:
     bash -c 'sudo rm -rf /var/lib/waydroid /home/.waydroid ~/waydroid ~/.share/waydroid ~/.local/share/applications/*aydroid* ~/.local/share/waydroid'