feat(layout): Implement toJSON in Neo.layout.Cube for Neural Link serialization (#8237)

Author: tobiu

src/layout/Cube.mjs

@@ -97,6 +97,27 @@ class Cube extends Card {
         sideZ_: 300
     }
 
+    /**
+     * Serializes the instance into a JSON-compatible object for the Neural Link.
+     * @returns {Object}
+     */
+    toJSON() {
+        return {
+            ...super.toJSON(),
+            activeFace                : this.activeFace,
+            activeIndex               : this.activeIndex,
+            fitContainer              : this.fitContainer,
+            hideInactiveCardsOnDestroy: this.hideInactiveCardsOnDestroy,
+            perspective               : this.perspective,
+            rotateX                   : this.rotateX,
+            rotateY                   : this.rotateY,
+            rotateZ                   : this.rotateZ,
+            sideX                     : this.sideX,
+            sideY                     : this.sideY,
+            sideZ                     : this.sideZ
+        }
+    }
+
     /**
      * @member {Function|null} #cachedVdomItemsRoot=null
      * @private