chore: Add just command for LACT to deck builds

system_files/deck/shared/usr/share/ublue-os/just/60-custom.just

@@ -48,6 +48,30 @@ autostart-sunshine:
     #!/usr/bin/bash
     systemctl enable --user --now sunshine.service
 
+# Install LACT for overclocking & undervolting AMD GPUs (For HTPC use only)
+install-lact:
+    #!/usr/bin/bash
+    IMAGE_INFO="/usr/share/ublue-os/image-info.json"
+    BASE_IMAGE_NAME=$(jq -r '."base-image-name"' < $IMAGE_INFO)
+    ublue-update --wait
+    if [[ ${BASE_IMAGE_NAME} == 'silverblue' ]]; then
+        echo 'Installing LACT Libadwaita...'
+        wget \
+          $(curl -s https://api.github.com/repos/ilya-zlobintsev/LACT/releases/latest | \
+          jq -r ".assets[] | select(.name | test(\"lact-libadwaita.*fedora-$(rpm -E %fedora)\")) | .browser_download_url") \
+          -O /tmp/lact.rpm
+    else
+        echo 'Installing LACT...'
+        wget \
+          $(curl -s https://api.github.com/repos/ilya-zlobintsev/LACT/releases/latest | \
+          jq -r ".assets[] | select(.name | test(\"lact-[0-9].*fedora-$(rpm -E %fedora)\")) | .browser_download_url") \
+          -O /tmp/lact.rpm
+    fi
+    rpm-ostree install --apply-live -y /tmp/lact.rpm
+    sudo systemctl enable --now lactd
+    rm /tmp/lact.rpm
+    echo 'Complete.'
+
 # Install Decky Loader (https://github.com/SteamDeckHomebrew/decky-loader)
 get-decky:
     #!/usr/bin/bash