refactor: Resolve import and constant duplication issues in AI and game modules

game.js

@@ -1,6 +1,8 @@
 /**********************************************************************
  * GAME CORE
  **********************************************************************/
+// Import AI functions
+import { updateCitizen, updateAnimal } from './ai.js';
 let frameCount = 0;
 let money = 5000;  // Start with 5000
 let purchaseMode = null;
@@ -122,7 +124,13 @@ function update() {
   frameCount++;
 
   // Citizens
-  citizens.forEach((cit) => updateCitizen(cit));
+  citizens.forEach((cit) => {
+    if(typeof updateCitizen === 'function') {
+      updateCitizen(cit);
+    } else {
+      console.error("updateCitizen function is not defined!");
+    }
+  });
 
   // Animals
   animals.forEach((ani) => {