added to remote repo

frontend/src/api.js

@@ -0,0 +1,26 @@
+import axios from 'axios';
+
+export const api = axios.create({
+  baseURL: import.meta.env.VITE_API_URL || 'http://localhost:3000/api',
+  timeout: 15000,
+});
+
+const token = window.localStorage.getItem('incusBackupApiToken') || import.meta.env.VITE_API_TOKEN;
+if (token) {
+  api.defaults.headers.common.Authorization = `Bearer ${token}`;
+}
+
+export function setApiToken(tokenValue) {
+  const token = String(tokenValue || '');
+  if (token) {
+    window.localStorage.setItem('incusBackupApiToken', token);
+    api.defaults.headers.common.Authorization = `Bearer ${token}`;
+    return;
+  }
+  window.localStorage.removeItem('incusBackupApiToken');
+  delete api.defaults.headers.common.Authorization;
+}
+
+export function errorMessage(error) {
+  return error.response?.data?.error || error.message || 'Request failed.';
+}