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/regeneratorAsync.js

@@ -0,0 +1,8 @@
+var regeneratorAsyncGen = require("./regeneratorAsyncGen.js");
+function _regeneratorAsync(n, e, r, t, o) {
+  var a = regeneratorAsyncGen(n, e, r, t, o);
+  return a.next().then(function (n) {
+    return n.done ? n.value : a.next();
+  });
+}
+module.exports = _regeneratorAsync, module.exports.__esModule = true, module.exports["default"] = module.exports;