Stable identity for this block's first item.
User payload items stored in this block.
OptionallengthNumber of entries represented by a tombstoned range.
OptionalpendingRange waiting for missing predecessor dependencies during hydration.
Stable previous block or item id, or '0' for root-level blocks.
Block record used by snapshots and deltas.
itemsare live payload references. Consumers that mutate items outside CRList operations must provide their own isolation first.