Build only the module list the bar is showing

The center section declares both an anchored and an unanchored
arrangement and shows whichever fits, but a hidden ModuleList is still a
loaded Loader. With a center anchor set — the default — every center
module was therefore mounted twice for the life of the session: two IPC
handlers registered for the same target, two clocks ticking, two of every
timer and network fetch behind them, one set of which nothing could
reach.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

shell/plugins/bar/Bar.qml

@@ -1321,6 +1321,12 @@ Item {
     property string region: ""
 
     visible: entries.length > 0
+    // A hidden list must not build its modules. The center section declares
+    // both an anchored and an unanchored arrangement and shows whichever
+    // fits, so leaving the other one loaded mounts every center module
+    // twice — two IPC handlers registered for the same target, two clocks
+    // ticking, two of every timer and fetch behind them.
+    active: visible && entries.length > 0
     sourceComponent: root.vertical ? verticalModuleList : horizontalModuleList
     width: item ? item.implicitWidth : 0
     height: item ? item.implicitHeight : 0