Qualify shell palette references for Qt 6.12 (#14553)

test/shell.d/fixtures/network-captive-portal/shell.qml

@@ -2,6 +2,7 @@ import QtQuick
 import Quickshell
 import Quickshell.Networking
 import qs.Commons
+import qs.Commons as Commons
 import "mocks"
 import "network" as Network
 
@@ -21,9 +22,9 @@ ShellRoot {
     Network.Panel {
       id: panel
       bar: QtObject {
-        property color foreground: Color.foreground
-        property color barForeground: Color.foreground
-        property color urgent: Color.urgent
+        property color foreground: Commons.Color.foreground
+        property color barForeground: Commons.Color.foreground
+        property color urgent: Commons.Color.urgent
         property string fontFamily: Style.font.family
         property string position: "top"
         property int barSize: 24