fix: add wayland dev headers and scanner for pywayland build on NixOS

configs/quickshell/services/ai/AiMessageData.qml

@@ -0,0 +1,21 @@
+import QtQuick;
+
+/**
+ * Represents a message in an AI conversation. (Kind of) follows the OpenAI API message structure.
+ */
+QtObject {
+    property string role
+    property string content
+    property string rawContent
+    property string model
+    property bool thinking: true
+    property bool done: false
+    property var annotations: []
+    property var annotationSources: []
+    property list<string> searchQueries: []
+    property string functionName
+    property var functionCall
+    property string functionResponse
+    property bool functionPending: false
+    property bool visibleToUser: true
+}