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/css-tree/lib/data-patch.js

@@ -0,0 +1,6 @@
+import { createRequire } from 'module';
+
+const require = createRequire(import.meta.url);
+const patch = require('../data/patch.json');
+
+export default patch;