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/superPropGet.js

@@ -0,0 +1,9 @@
+var get = require("./get.js");
+var getPrototypeOf = require("./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;
+}
+module.exports = _superPropGet, module.exports.__esModule = true, module.exports["default"] = module.exports;