v2 - 2026-10-08 - Relationship field values and Documents API references

Relationships can carry field values. Relationships returned by List relationships and by entity reads include a fields object keyed by field ID; fields without a value are omitted. Create relationship accepts fields, and Retrieve entity configuration lists the fields each relationship can carry.
Beta Pb-Beta: document-references: a document reference now carries the Documents API documentId and links to /v2/documents/{documentId} instead of /v2/editor/documents/{id}. Read and replace the content as PBFM through the Documents API.
Removed schemas from the specification that no public operation used. Generated clients may drop the corresponding types; no endpoint changed.