An anonymous caller could degrade `/sql` availability by streaming WebSocket frames many times larger than the operator-configured per-connection limit. The `/sql` upgrade handler accepted anonymous connections and did not propagate `SURREAL_WEBSOCKET_MAX_MESSAGE_SIZE` to the WebSocket protocol layer — incoming bytes accumulated in the per-connection read buffer before `check_anon` could reject the query, so the memory cost was incurred regardless of whether the caller could ever execute Surreal