Fixed export statements in DialogueSystem & TwinBondSystem - removed 'export default' for browser compatibility

src/systems/DialogueSystem.js

@@ -15,7 +15,7 @@
  * @date 2025-12-23
  */
 
-export default class DialogueSystem {
+class DialogueSystem {
     constructor(scene) {
         this.scene = scene;
 

src/systems/TwinBondSystem.js

@@ -23,7 +23,7 @@
  * @date 2025-12-23
  */
 
-export default class TwinBondSystem {
+class TwinBondSystem {
     constructor(scene) {
         this.scene = scene;