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/@babel/runtime/helpers/createForOfIteratorHelperLoose.js

@@ -0,0 +1,19 @@
+var unsupportedIterableToArray = require("./unsupportedIterableToArray.js");
+function _createForOfIteratorHelperLoose(r, e) {
+  var t = "undefined" != typeof Symbol && r[Symbol.iterator] || r["@@iterator"];
+  if (t) return (t = t.call(r)).next.bind(t);
+  if (Array.isArray(r) || (t = unsupportedIterableToArray(r)) || e && r && "number" == typeof r.length) {
+    t && (r = t);
+    var o = 0;
+    return function () {
+      return o >= r.length ? {
+        done: !0
+      } : {
+        done: !1,
+        value: r[o++]
+      };
+    };
+  }
+  throw new TypeError("Invalid attempt to iterate non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method.");
+}
+module.exports = _createForOfIteratorHelperLoose, module.exports.__esModule = true, module.exports["default"] = module.exports;