Updates a profile through delta. Omitted top-level scalar and personal-information fields remain unchanged. Use clearTopLevelFields or the supported nested clearFields to explicitly clear them.

Document updates use delta.idDocs.upsert and delta.idDocs.remove:

• Each upsert replaces a complete document. Resend every identity field and file slot to retain. Omitting files on a DOC replacement clears its stored file map.
• Provide idDocId to replace an existing record; omit it to create a record.
• A DOC upsert removes other DOC records of the same idDocType. A SELFIE upsert removes other SELFIE records, even without remove entries.
• Each request allows at most one SELFIE upsert and one DOC upsert per idDocType.

Every upsert requires category. DOC requires idDocType for creation and replacement, and non-empty files for creation. SELFIE requires non-empty files for both. The old per-category groups are rejected. Collection validation is atomic: invalid items reject the request without partial updates.

On success returns a write acknowledgment (profileId, externalUserId, status). Use GET to load the full Profile resource.