9.2 ADR-2: Confluence REST API v2, with one v1 exception

Status: accepted

Context: Confluence Cloud offers v1 and v2. v1 is feature-complete but on the way out; v2 is the documented future and has no endpoint for creating attachments.

Decision: Generate the client from the OpenAPI v2 specification. Keep exactly one v1 operation: PUT /rest/api/content/{id}/child/attachment.

Consequences: The client stays aligned with the contract Atlassian maintains, at the cost of supporting Cloud only — Server and Data Center are out. The v1 exception is a known, isolated risk tracked upstream as CONFCLOUD-77196, which sits in Future Consideration without an ETA. The operation is not deprecated, so the exception is stable for now.