OSS-first docs
These docs teach the open system first: contracts, generated surfaces, runtimes, governance, and incremental adoption. Studio shows up as the operating layer on top, not as the source of truth.
Appends a comment to a review. Does not advance state. `visibility` is one of `'thread'` (visible to all participants) | `'private-to-assignee'` (visible only to the current assignee and the commenter).
Per SEAMS §1.3 (S-11), emits one `audit.event.append` with kind `review.commented` (retention class `operational`).
Capability: `review.act` for posting; `review.read` for thread reads. Auditor persona may read but cannot post — the UI renders the post button disabled with a read-only tooltip per SEAMS §1.5.