- Replace toolbar QR popover with a window sheet per sketch: top hint,
280pt white-backed QR, copy-image / save-image / copy-ss:// actions
and a Done button; all buttons share a 260pt min label width
- Freeze share payload and suggested file name at presentation time;
transient "copied" feedback on copy actions
- Add ImageClipboard seam (PNG normative type + TIFF in AppKit adapter)
and QrImageSaver seam (NSSavePanel PNG, sanitized suggested name)
- Register new typed failures in the presentation whitelist; extend
platform-effects architecture guard and seam tests
- Record spec in docs/design/server-share-sheet.md; GLOSSARY server
share now covers saved QR image files
Qiu Yuzhou