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/object-inspect/example/inspect.js

@@ -0,0 +1,10 @@
+'use strict';
+
+/* eslint-env browser */
+var inspect = require('../');
+
+var d = document.createElement('div');
+d.setAttribute('id', 'beep');
+d.innerHTML = '<b>wooo</b><i>iiiii</i>';
+
+console.log(inspect([d, { a: 3, b: 4, c: [5, 6, [7, [8, [9]]]] }]));