fix: centralize app API URL fallbacks

src/axiosConfig.ts

@@ -1,11 +1,12 @@
 import axios from 'axios';
+import { API_BASE as CONFIG_API_BASE } from './config/apiConfig';
 import { logger } from './debugConfig';
 
 // Use development backend URL if no custom URL is provided
-const baseURL = import.meta.env.VITE_API_BASE || 'http://localhost:8080';
+const baseURL = CONFIG_API_BASE;
 
-if (!import.meta.env.VITE_API_BASE) {
-  logger.warn('axios', '⚠️ VITE_API_BASE not set, defaulting to http://localhost:8080');
+if (!import.meta.env.VITE_API_BASE && !import.meta.env.VITE_API_URL) {
+  logger.warn('axios', '⚠️ VITE_API_BASE not set, using relative /api fallback');
 }
 
 const instance = axios.create({