The backend half of the sweep RD-18 did for the front end. git blame holds the provenance and stays correct when the code moves; the comment names a closed ticket and tells the reader nothing the sentence around it does not. public/letter.css and LetterHtml.golden.html change together, because the renderer inlines the CSS and the golden file snapshots the result. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>