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/esm/superPropGet.js

@@ -0,0 +1,9 @@
+import get from "./get.js";
+import getPrototypeOf from "./getPrototypeOf.js";
+function _superPropGet(t, o, e, r) {
+  var p = get(getPrototypeOf(1 & r ? t.prototype : t), o, e);
+  return 2 & r && "function" == typeof p ? function (t) {
+    return p.apply(e, t);
+  } : p;
+}
+export { _superPropGet as default };