Size the indicator tray from block implicit sizes

Deriving the tray's implicit size from childrenRect fed layout results
back into the bindings that produced them, tripping implicitWidth
binding loop warnings. Compute it from the active and inactive blocks'
own implicit sizes instead, and center the loaded blocks rather than
anchor-filling containers that are sized by their content. The contract
test now instantiates the tray to check the collapse/expand cycle and
fails on any implicitWidth binding loop in the log.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

shell/plugins/bar/widgets/Indicators.qml

@@ -154,8 +154,12 @@ BarWidget {
 
   onIndicatorEntriesChanged: syncActiveIndicatorOrder()
 
-  implicitWidth: root.vertical ? verticalIndicators.implicitWidth : horizontalIndicators.implicitWidth
-  implicitHeight: root.vertical ? verticalIndicators.implicitHeight : horizontalIndicators.implicitHeight
+  implicitWidth: root.vertical
+    ? Math.max(activeVerticalBlock.implicitWidth, inactiveVerticalArea.implicitWidth)
+    : activeHorizontalBlock.implicitWidth + inactiveHorizontalArea.implicitWidth
+  implicitHeight: root.vertical
+    ? activeVerticalBlock.implicitHeight + inactiveVerticalArea.implicitHeight
+    : Math.max(activeHorizontalBlock.implicitHeight, inactiveHorizontalArea.implicitHeight)
 
   IpcHandler {
     target: "omarchy.indicators"
@@ -187,6 +191,7 @@ BarWidget {
     }
 
     ActiveIndicatorBlock {
+      id: activeHorizontalBlock
       indicatorsModule: root
       indicatorModel: activeIndicatorModel
       horizontal: true
@@ -204,7 +209,7 @@ BarWidget {
 
       IndicatorBlock {
         id: inactiveHorizontalBlock
-        anchors.fill: parent
+        anchors.verticalCenter: parent.verticalCenter
         indicatorsModule: root
         indicatorEntries: root.indicatorEntries
         indicatorBlock: "inactive"
@@ -229,6 +234,7 @@ BarWidget {
     }
 
     ActiveIndicatorBlock {
+      id: activeVerticalBlock
       indicatorsModule: root
       indicatorModel: activeIndicatorModel
       horizontal: false
@@ -246,7 +252,7 @@ BarWidget {
 
       IndicatorBlock {
         id: inactiveVerticalBlock
-        anchors.fill: parent
+        anchors.horizontalCenter: parent.horizontalCenter
         indicatorsModule: root
         indicatorEntries: root.indicatorEntries
         indicatorBlock: "inactive"
@@ -272,15 +278,15 @@ BarWidget {
     property bool horizontal: true
     property bool reportActiveState: false
 
-    implicitWidth: blockLoader.item ? blockLoader.item.childrenRect.width : 0
-    implicitHeight: blockLoader.item ? blockLoader.item.childrenRect.height : 0
+    implicitWidth: blockLoader.item ? blockLoader.item.implicitWidth : 0
+    implicitHeight: blockLoader.item ? blockLoader.item.implicitHeight : 0
     width: implicitWidth
     height: implicitHeight
 
     Loader {
       id: blockLoader
 
-      anchors.fill: parent
+      anchors.centerIn: parent
       sourceComponent: activeIndicatorBlockRoot.horizontal ? horizontalActiveIndicatorBlock : verticalActiveIndicatorBlock
     }
 
@@ -334,15 +340,15 @@ BarWidget {
     property bool horizontal: true
     property bool reportActiveState: false
 
-    implicitWidth: blockLoader.item ? blockLoader.item.childrenRect.width : 0
-    implicitHeight: blockLoader.item ? blockLoader.item.childrenRect.height : 0
+    implicitWidth: blockLoader.item ? blockLoader.item.implicitWidth : 0
+    implicitHeight: blockLoader.item ? blockLoader.item.implicitHeight : 0
     width: implicitWidth
     height: implicitHeight
 
     Loader {
       id: blockLoader
 
-      anchors.fill: parent
+      anchors.centerIn: parent
       sourceComponent: indicatorBlockRoot.horizontal ? horizontalIndicatorBlock : verticalIndicatorBlock
     }