right sidebar: move audio controls to dialogs

dots/.config/quickshell/ii/modules/common/Config.qml

@@ -139,6 +139,7 @@ Singleton {
                 property string networkEthernet: "kcmshell6 kcm_networkmanagement"
                 property string taskManager: "plasma-systemmonitor --page-name Processes"
                 property string terminal: "kitty -1" // This is only for shell actions
+                property string volumeMixer: `~/.config/hypr/hyprland/scripts/launch_first_available.sh "pavucontrol-qt" "pavucontrol"`
             }
 
             property JsonObject background: JsonObject {

dots/.config/quickshell/ii/modules/common/widgets/StyledSlider.qml

@@ -165,7 +165,7 @@ Slider {
             TrackDot {
                 required property real modelData
                 value: modelData
-                anchors.verticalCenter: parent.verticalCenter
+                anchors.verticalCenter: parent?.verticalCenter
             }
         }
     }

dots/.config/quickshell/ii/modules/common/widgets/WindowDialogSectionHeader.qml

@@ -0,0 +1,13 @@
+import QtQuick
+import Quickshell
+import qs.modules.common
+import qs.modules.common.functions
+import qs.modules.common.widgets
+
+StyledText {
+    text: "Section"
+    font {
+        pixelSize: Appearance.font.pixelSize.large
+        family: Appearance.font.family.title
+    }
+}