Implement environment variable setup for frontend; create .env.production and .env.development files if they don't exist, and update API URLs in frontend components to use dynamic API_BASE_URL for improved configuration management.

frontend/src/stores/authStore.js

@@ -1,7 +1,8 @@
 import { defineStore } from 'pinia'
 import { ref } from 'vue'
+import { API_BASE_URL } from '@/config/api'
 
-const API_URL = 'http://localhost:3010/api'
+const API_URL = API_BASE_URL
 
 export const useAuthStore = defineStore('auth', () => {
   const user = ref(null)