feat: add internal event for dashboard entity updates

Author: fulleni

lib/dashboard/bloc/dashboard_event.dart

@@ -10,3 +10,8 @@ sealed class DashboardEvent extends Equatable {
 
 /// Event to load the dashboard summary data.
 final class DashboardSummaryLoaded extends DashboardEvent {}
+
+/// Internal event triggered when a listened-to entity is updated.
+final class _DashboardEntityUpdated extends DashboardEvent {
+  const _DashboardEntityUpdated();
+}