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/_baseSampleSize.js

@@ -0,0 +1,18 @@
+var baseClamp = require('./_baseClamp'),
+    shuffleSelf = require('./_shuffleSelf'),
+    values = require('./values');
+
+/**
+ * The base implementation of `_.sampleSize` without param guards.
+ *
+ * @private
+ * @param {Array|Object} collection The collection to sample.
+ * @param {number} n The number of elements to sample.
+ * @returns {Array} Returns the random elements.
+ */
+function baseSampleSize(collection, n) {
+  var array = values(collection);
+  return shuffleSelf(array, baseClamp(n, 0, array.length));
+}
+
+module.exports = baseSampleSize;