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/compact.js

@@ -0,0 +1,31 @@
+/**
+ * Creates an array with all falsey values removed. The values `false`, `null`,
+ * `0`, `-0`, `0n`, `""`, `undefined`, and `NaN` are falsy.
+ *
+ * @static
+ * @memberOf _
+ * @since 0.1.0
+ * @category Array
+ * @param {Array} array The array to compact.
+ * @returns {Array} Returns the new array of filtered values.
+ * @example
+ *
+ * _.compact([0, 1, false, 2, '', 3]);
+ * // => [1, 2, 3]
+ */
+function compact(array) {
+  var index = -1,
+      length = array == null ? 0 : array.length,
+      resIndex = 0,
+      result = [];
+
+  while (++index < length) {
+    var value = array[index];
+    if (value) {
+      result[resIndex++] = value;
+    }
+  }
+  return result;
+}
+
+module.exports = compact;