Constant MAX_BATCH_BYTES 

pub const MAX_BATCH_BYTES: u64 = _; // 268_435_456u64

Per-batch measured-size cap (256 MiB) — a single decoded batch larger than this is BundleError::TooLarge, independent of the running total. This is a post-materialization reject: the batch is decoded and measured before it is checked, so the reader’s true transient peak is ~one batch (bounded by MAX_BATCH_ROWS × the column widths), not the whole table — the documented residual #36’s adversarial fixtures probe.