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/pick.js

@@ -0,0 +1,25 @@
+var basePick = require('./_basePick'),
+    flatRest = require('./_flatRest');
+
+/**
+ * Creates an object composed of the picked `object` properties.
+ *
+ * @static
+ * @since 0.1.0
+ * @memberOf _
+ * @category Object
+ * @param {Object} object The source object.
+ * @param {...(string|string[])} [paths] The property paths to pick.
+ * @returns {Object} Returns the new object.
+ * @example
+ *
+ * var object = { 'a': 1, 'b': '2', 'c': 3 };
+ *
+ * _.pick(object, ['a', 'c']);
+ * // => { 'a': 1, 'c': 3 }
+ */
+var pick = flatRest(function(object, paths) {
+  return object == null ? {} : basePick(object, paths);
+});
+
+module.exports = pick;