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/_isLaziable.js

@@ -0,0 +1,28 @@
+var LazyWrapper = require('./_LazyWrapper'),
+    getData = require('./_getData'),
+    getFuncName = require('./_getFuncName'),
+    lodash = require('./wrapperLodash');
+
+/**
+ * Checks if `func` has a lazy counterpart.
+ *
+ * @private
+ * @param {Function} func The function to check.
+ * @returns {boolean} Returns `true` if `func` has a lazy counterpart,
+ *  else `false`.
+ */
+function isLaziable(func) {
+  var funcName = getFuncName(func),
+      other = lodash[funcName];
+
+  if (typeof other != 'function' || !(funcName in LazyWrapper.prototype)) {
+    return false;
+  }
+  if (func === other) {
+    return true;
+  }
+  var data = getData(other);
+  return !!data && func === data[0];
+}
+
+module.exports = isLaziable;