The QR login page countdown timer compared the server's UTC expiration
timestamp against the client's local clock, causing the QR code to appear
immediately expired when the client clock was ahead of the server.
Changes:
- Add ttl_seconds field to CreateChallengeResponse (seconds until expiry)
- Frontend countdown now uses relative elapsed time since response was
received, eliminating clock-skew issues
- Mobile app: replace alert-only QR button with actual camera-based
QR code scanner using expo-camera
- Add QRScannerScreen with barcode scanning, permission handling, and
scan area overlay
- Update camera permission description to mention QR code scanning
- Add tests for ttl_seconds computation
Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>
copilot-swe-agent[bot]