B2 of the Matrix protocol-gaps roadmap, gate-green (688 tests):
- Enable QR verification methods (show/scan/reciprocate) in initMatrix.
- Extend DeviceVerification: the Ready step offers your own QR (byte-mode encode
via qrcode), a camera 'Scan their QR code' flow, and an emoji fallback; the
Started step routes reciprocate → a confirm step (useVerifierShowReciprocateQr)
or SAS as before.
- New QrScanner component: getUserMedia + jsQR, handing the raw binaryData bytes
to request.scanQRCode (BarcodeDetector is string-only, so can't be used).
- Adds qrcode + jsqr (small, pure-JS, client-only); build-verified under rolldown.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
