Function upsert_consumer 

async fn upsert_consumer(
    __arg0: State<Arc<SharedState>>,
    __arg1: Path<String>,
    __arg2: Json<ConsumerConfig>,
) -> impl IntoResponse

PUT /api/consumers/{name} — creates or replaces the named consumer (the path name overrides any name in the body), matching the policies endpoint’s upsert semantics. Returns {"status": "updated"}.

Errors: 400 Bad Request if the store rebuild rejects the config.