feat: add NotificationOverview and NotificationOverviewLoader for notification history overview {alpha}

modules/bar/widgets/NotificationButton.qml

@@ -13,22 +13,63 @@ MouseArea {
     cursorShape: Qt.PointingHandCursor
 
     onClicked: {
-        NotificationS.soundEnabled = !NotificationS.soundEnabled
+        NotificationS.toggleOverview()
     }
-    
+
     Rectangle {
         anchors.fill: parent
-        color: "transparent"
+        color: notificationButton.containsMouse || NotificationS.overviewVisible ? Colors.tertiary : "transparent"
         radius: Config.radius_fun(notificationButton.height)
+        border.width: Config.border_width
+        border.color: notificationButton.containsMouse || NotificationS.overviewVisible ? Colors.tertiary_fg : "transparent"
 
         Text {
             id: notificationText
             anchors.centerIn: parent
-            // text: Quickshell.iconPath("discord") 
-            text: NotificationS.soundEnabled ? "󰂚" : "󰂛"
+            text: "󰂚"
             font.pixelSize: Config.bigIconSize(bar.height)
             font.family: Config.font
-            color: Colors.secondaryContainer_fg
+            color: NotificationS.overviewVisible ? Colors.tertiary_fg : Colors.secondaryContainer_fg
+        }
+
+        // count badge
+        Rectangle {
+            id: badge
+            visible: NotificationS.trackedNotifications.values.length > 0
+            width: badgeText.implicitWidth + 6
+            height: badgeText.implicitHeight + 4
+            radius: height / 2
+            color: Colors.errorContainer
+            border.width: 1
+            border.color: Colors.error
+            anchors.top: parent.top
+            anchors.right: parent.right
+            anchors.topMargin: 2
+            anchors.rightMargin: 2
+            Text {
+                id: badgeText
+                anchors.centerIn: parent
+                text: NotificationS.trackedNotifications.values.length > 99 ? "99+" : NotificationS.trackedNotifications.values.length
+                font.family: Config.font
+                font.pixelSize: Config.labelSize(bar.height) * 0.6
+                font.bold: true
+                color: Colors.error_fg
+            }
+        }
+
+        // muted indicator dot
+        Rectangle {
+            visible: !NotificationS.soundEnabled
+            width: 8
+            height: 8
+            radius: 4
+            color: Colors.error
+            border.width: 1
+            border.color: Colors.error_fg
+            anchors.bottom: parent.bottom
+            anchors.right: parent.right
+            anchors.bottomMargin: 3
+            anchors.rightMargin: 3
         }
 
         // Image{