Fix: Riverpod 3.0 StreamProvider stops emitting because updates are filtered by ==
In Riverpod 3.0 every provider filters listener notifications with ==, not identity. A StreamProvider that re-emits the same mutable object stops rebuilding the UI after the first frame. Here is why it happens and three ways to fix it. Tested on flutter_riverpod 3.3.2, Flutter 3.44, Dart 3.x.