refactor: Remove ES6 module syntax and reorder script loading

game.js

@@ -1,8 +1,7 @@
 /**********************************************************************
  * GAME CORE
  **********************************************************************/
-// Import AI functions
-import { updateCitizen, updateAnimal } from './ai.js';
+// AI functions are defined in ai.js and loaded via script tag
 let frameCount = 0;
 let money = 5000;  // Start with 5000
 let purchaseMode = null;