feat(frontend): add API client, layout, and routing

- Create Axios-based API client with sources, jobs, and dashboard endpoints
- Add responsive Layout component with navigation sidebar
- Set up React Router with Dashboard, Backups, and Settings routes
- Configure TanStack Query provider with default options
- Use lucide-react for navigation icons

frontend/node_modules/axios/lib/platform/node/classes/FormData.js

@@ -0,0 +1,3 @@
+import FormData from 'form-data';
+
+export default FormData;

frontend/node_modules/axios/lib/platform/node/classes/URLSearchParams.js

@@ -0,0 +1,4 @@
+'use strict';
+
+import url from 'url';
+export default url.URLSearchParams;