feat(gpu): add cardwire integration and gpu widget

services/GPU.qml

@@ -0,0 +1,12 @@
+pragma Singleton
+
+import Quickshell
+import Tshell.Cardwire
+
+Singleton {
+    id: root
+
+    readonly property bool connected: Cardwire.connected
+    readonly property CardwireGpu gpu: Cardwire.nvidiaGpu
+    readonly property url icon: `${Quickshell.shellPath("assets")}/icons/nvidia.svg`
+}