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/_baseReduce.js

@@ -0,0 +1,23 @@
+/**
+ * The base implementation of `_.reduce` and `_.reduceRight`, without support
+ * for iteratee shorthands, which iterates over `collection` using `eachFunc`.
+ *
+ * @private
+ * @param {Array|Object} collection The collection to iterate over.
+ * @param {Function} iteratee The function invoked per iteration.
+ * @param {*} accumulator The initial value.
+ * @param {boolean} initAccum Specify using the first or last element of
+ *  `collection` as the initial value.
+ * @param {Function} eachFunc The function to iterate over `collection`.
+ * @returns {*} Returns the accumulated value.
+ */
+function baseReduce(collection, iteratee, accumulator, initAccum, eachFunc) {
+  eachFunc(collection, function(value, index, collection) {
+    accumulator = initAccum
+      ? (initAccum = false, value)
+      : iteratee(accumulator, value, index, collection);
+  });
+  return accumulator;
+}
+
+module.exports = baseReduce;