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/replace.js

@@ -0,0 +1,29 @@
+var toString = require('./toString');
+
+/**
+ * Replaces matches for `pattern` in `string` with `replacement`.
+ *
+ * **Note:** This method is based on
+ * [`String#replace`](https://mdn.io/String/replace).
+ *
+ * @static
+ * @memberOf _
+ * @since 4.0.0
+ * @category String
+ * @param {string} [string=''] The string to modify.
+ * @param {RegExp|string} pattern The pattern to replace.
+ * @param {Function|string} replacement The match replacement.
+ * @returns {string} Returns the modified string.
+ * @example
+ *
+ * _.replace('Hi Fred', 'Fred', 'Barney');
+ * // => 'Hi Barney'
+ */
+function replace() {
+  var args = arguments,
+      string = toString(args[0]);
+
+  return args.length < 3 ? string : string.replace(args[1], args[2]);
+}
+
+module.exports = replace;