Tapping "Scan a QR code" crashed the app on Android:
com.facebook.react.common.JavascriptException: Error:
CameraFactory.createObjectOutput(...): java.lang.Error:
CameraObjectOutput is not available on Android!
`useObjectOutput` is Apple Vision only — the comment claiming v5 ships a
cross-platform code scanner in core was wrong, and the native factory throws as
soon as the screen mounts. The Barcode Scanner output is the cross-platform one
(MLKit on Android, Vision on iOS); it is attached to the same `<Camera>` via
`outputs`, scans `qr-code` only, and keeps the hand-paste fallback. The scan
callback now takes the barcode values directly instead of the object-output
shape.
The service mints /api/alarm/a/{alertId}#{token} with no host, so the QR renders against the configured instance and keeps working when the instance moves or is reached by another name. The scanner now matches path shape and fragment and never the host, so legacy alarm.dcntrlized.org codes and other instances codes still join; error copy distinguishes a malformed code from a wrong-alert token.