One entry in a structured Document Section Changes request. It supplies the section key to add or modify, the Document Section marker to store at that key, and the contracts that belong to the section. Change-management workflows convert this structured entry into deterministic `/contracts` patches. The `sectionKey` is the key under `/contracts` for the Document Section marker. The `section` node should be a Workflows/Document Section whose `relatedContracts` corresponds to the keys in `contracts`, unless the workflow fills or normalizes that relationship. The `contracts` map contains the actual contract nodes to add or replace for the section. This representation is intentionally higher-level than raw JSON patch. It lets policies require that behavioral changes be reviewed as sections rather than as arbitrary pointer edits.