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/propertyOf.js

@@ -0,0 +1,30 @@
+var baseGet = require('./_baseGet');
+
+/**
+ * The opposite of `_.property`; this method creates a function that returns
+ * the value at a given path of `object`.
+ *
+ * @static
+ * @memberOf _
+ * @since 3.0.0
+ * @category Util
+ * @param {Object} object The object to query.
+ * @returns {Function} Returns the new accessor function.
+ * @example
+ *
+ * var array = [0, 1, 2],
+ *     object = { 'a': array, 'b': array, 'c': array };
+ *
+ * _.map(['a[2]', 'c[0]'], _.propertyOf(object));
+ * // => [2, 0]
+ *
+ * _.map([['a', '2'], ['c', '0']], _.propertyOf(object));
+ * // => [2, 0]
+ */
+function propertyOf(object) {
+  return function(path) {
+    return object == null ? undefined : baseGet(object, path);
+  };
+}
+
+module.exports = propertyOf;