feat: add NIconTabButton widget for icon-only tabs

Widgets/NIconTabButton.qml

@@ -0,0 +1,64 @@
+import QtQuick
+import QtQuick.Controls
+import QtQuick.Layouts
+import qs.Commons
+import qs.Widgets
+
+Rectangle {
+  id: root
+
+  // Public properties
+  property string icon: ""
+  property bool checked: false
+  property int tabIndex: 0
+
+  // Internal state
+  property bool isHovered: false
+
+  signal clicked
+
+  // Sizing
+  Layout.fillWidth: true
+  Layout.fillHeight: true
+
+  // Styling
+  radius: Style.radiusXS
+  color: root.checked ? Color.mPrimary : (root.isHovered ? Color.mHover : Color.mSurface)
+
+  Behavior on color {
+    ColorAnimation {
+      duration: Style.animationFast
+      easing.type: Easing.OutCubic
+    }
+  }
+
+  NIcon {
+    id: tabIcon
+    anchors.centerIn: parent
+    icon: root.icon
+    pointSize: Style.fontSizeL
+    color: root.checked ? Color.mOnPrimary : root.isHovered ? Color.mOnHover : Color.mOnSurface
+
+    Behavior on color {
+      ColorAnimation {
+        duration: Style.animationFast
+        easing.type: Easing.OutCubic
+      }
+    }
+  }
+
+  MouseArea {
+    anchors.fill: parent
+    hoverEnabled: true
+    cursorShape: Qt.PointingHandCursor
+    onEntered: root.isHovered = true
+    onExited: root.isHovered = false
+    onClicked: {
+      root.clicked();
+      // Update parent NTabBar's currentIndex
+      if (root.parent && root.parent.parent && root.parent.parent.currentIndex !== undefined) {
+        root.parent.parent.currentIndex = root.tabIndex;
+      }
+    }
+  }
+}