Updates a KYB application with business information, usage details, beneficiaries, and file metadata. Cannot update a KYB that has already been processed (returns 403).

The request body is organized in sections:

• nature_of_business — Company identification and legal information
• usage_of_account — Intended use, transaction volumes, source of funds
• business_files — File-related metadata (signature type, public registry)
• beneficiaries — Shareholder confirmation and beneficiaries list