refactor(ui): consolidate Theme.qml tokens and replace unicode glyphs with SVG icons

src/pygui/ISC/Tabs/components/StreamStatsDialog.qml

@@ -1,6 +1,7 @@
 import QtQuick
 import QtQuick.Layouts
 import QtQuick.Controls
+import QtQuick.Controls.impl
 import ISC
 
 // ===== Stream Stats Dialog =====
@@ -72,7 +73,6 @@ Popup {
             }
 
             Button {
-                text: "✕"
                 flat: true
                 Layout.preferredWidth: 32
                 Layout.preferredHeight: 32
@@ -82,11 +82,13 @@ Popup {
                     radius: Theme.radiusXs
                     color: parent.hovered ? Theme.buttonNeutralHover : "transparent"
                 }
-                contentItem: Label {
-                    text: parent.text
+                contentItem: IconImage {
+                    source: "../icons/x.svg"
+                    width: 14; height: 14
+                    sourceSize.width: 14
+                    sourceSize.height: 14
                     color: Theme.bodyColor
-                    horizontalAlignment: Text.AlignHCenter
-                    verticalAlignment: Text.AlignVCenter
+                    anchors.centerIn: parent
                 }
             }
         }