refactor: enhance TimerPage layout and functionality; update theme and tokens for improved design consistency

- Refactored TimerPage component to improve layout and user experience.
- Updated theme configuration to utilize design tokens for better maintainability.
- Introduced new tokens for colors and typography to align with design principles.
- Simplified state management and improved timer functionality.
- Enhanced accessibility and responsiveness of UI elements.

desktop/kadence_desktop/qml/components/SectionTitle.qml

@@ -0,0 +1,31 @@
+// An eyebrow label with a rule running to the right edge.
+import QtQuick
+import QtQuick.Controls
+import QtQuick.Layouts
+
+import ".."
+
+RowLayout {
+    property string text: ""
+    property string trailing: ""
+
+    Layout.fillWidth: true
+    spacing: 10
+
+    Label {
+        text: parent.text.toUpperCase()
+        color: Theme.muted
+        font.pixelSize: 10
+        font.letterSpacing: 1.3
+        font.weight: Font.DemiBold
+        font.family: Theme.sansFamily
+    }
+    Rectangle { Layout.fillWidth: true; height: 1; color: Theme.rule }
+    Label {
+        visible: parent.trailing !== ""
+        text: parent.trailing
+        color: Theme.faint
+        font.pixelSize: 11
+        font.family: Theme.sansFamily
+    }
+}