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/lodash/fp/pullAllBy.js

@@ -0,0 +1,5 @@
+var convert = require('./convert'),
+    func = convert('pullAllBy', require('../pullAllBy'));
+
+func.placeholder = require('./placeholder');
+module.exports = func;