A collapsed Preview row under every markup editor: issue and MR create and edit, their comments, release create and edit, and a .md, .markdown or .org file in the file editor. It renders the draft with FormattedBodyView, the view the app's threads use, at the size the app shows that text (body size for bodies, notes and files; comment size for comments). Like the threads, it resolves no autolinks; the web's preview does.
- MarkupPreview(text:format:identifier:) and MarkupPreview.format(forFile:) (org / md / none by extension).
- Each editor passes the format it already sends.
- Live suite: testMarkupPreviewFlow types a bold comment on the fixture issue, expands the preview, checks the markers are gone, attaches a screenshot, and clears the draft without sending.
Unit tests: 491 passed on iOS 26.5 and 18.6; Release device build succeeds. Live: testMarkupPreviewFlow passed as ios-smoke on iOS 26.5 (light and dark) and iOS 18.6; the 26.5 screenshots show the rendered preview. The fixture issue has no comments after the runs.