Model rows stored the live Notification object in a ref role. When the
server destroyed the notification (sender close, DND untrack, dismiss)
the role became a dangling C++ pointer, and the next read segfaulted in
QQmlListModel::data — typically when replaying history over IPC. Track
live notifications in a JS map keyed by originalId instead, cleaned up
on close and untrack, where a stale reference degrades to a catchable
error instead of a crash.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
