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/isNativeFunction.js

@@ -0,0 +1,8 @@
+function _isNativeFunction(t) {
+  try {
+    return -1 !== Function.toString.call(t).indexOf("[native code]");
+  } catch (n) {
+    return "function" == typeof t;
+  }
+}
+module.exports = _isNativeFunction, module.exports.__esModule = true, module.exports["default"] = module.exports;