The in-app AI chat hardcoded type='page' and the shared createComment
swallowed anchoring failures silently, so agent comments never got a
text anchor/highlight.
- Forbid page-type comments for the agent: top-level comments are always
inline and require an exact `selection`; replies inherit the parent
anchor (stored as the historical `page` type).
- Throw and roll back the just-created comment when the selection cannot
be anchored, instead of leaving an orphan unanchored comment.
- Add comment-anchor module: text normalization (smart quotes, dashes,
nbsp, collapsed whitespace) and matching across adjacent text nodes
within a block, so selections crossing inline-code/bold/link anchor.
- Update create_comment (MCP) and createComment (ai-chat) tool schemas
and descriptions; add unit + mock-HTTP orchestration tests.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
