feat(content_management): add archived content events

- Create ArchivedContentEvent base class
- Add events for tab changes and loading archived content
- Implement restore and delete events for headlines, topics, and sources

Author: fulleni

lib/content_management/bloc/archived_content/archived_content_event.dart

@@ -0,0 +1,91 @@
+part of 'archived_content_bloc.dart';
+
+sealed class ArchivedContentEvent extends Equatable {
+  const ArchivedContentEvent();
+
+  @override
+  List<Object?> get props => [];
+}
+
+/// Event to change the active archived content tab.
+final class ArchivedContentTabChanged extends ArchivedContentEvent {
+  const ArchivedContentTabChanged(this.tab);
+
+  final ArchivedContentTab tab;
+
+  @override
+  List<Object?> get props => [tab];
+}
+
+/// Event to request loading of archived headlines.
+final class LoadArchivedHeadlinesRequested extends ArchivedContentEvent {
+  const LoadArchivedHeadlinesRequested({this.startAfterId, this.limit});
+
+  final String? startAfterId;
+  final int? limit;
+
+  @override
+  List<Object?> get props => [startAfterId, limit];
+}
+
+/// Event to request loading of archived topics.
+final class LoadArchivedTopicsRequested extends ArchivedContentEvent {
+  const LoadArchivedTopicsRequested({this.startAfterId, this.limit});
+
+  final String? startAfterId;
+  final int? limit;
+
+  @override
+  List<Object?> get props => [startAfterId, limit];
+}
+
+/// Event to request loading of archived sources.
+final class LoadArchivedSourcesRequested extends ArchivedContentEvent {
+  const LoadArchivedSourcesRequested({this.startAfterId, this.limit});
+
+  final String? startAfterId;
+  final int? limit;
+
+  @override
+  List<Object?> get props => [startAfterId, limit];
+}
+
+/// Event to restore an archived headline.
+final class RestoreHeadlineRequested extends ArchivedContentEvent {
+  const RestoreHeadlineRequested(this.id);
+
+  final String id;
+
+  @override
+  List<Object?> get props => [id];
+}
+
+/// Event to restore an archived topic.
+final class RestoreTopicRequested extends ArchivedContentEvent {
+  const RestoreTopicRequested(this.id);
+
+  final String id;
+
+  @override
+  List<Object?> get props => [id];
+}
+
+/// Event to restore an archived source.
+final class RestoreSourceRequested extends ArchivedContentEvent {
+  const RestoreSourceRequested(this.id);
+
+  final String id;
+
+  @override
+  List<Object?> get props => [id];
+}
+
+/// Event to permanently delete an archived headline.
+final class DeleteHeadlineForeverRequested extends ArchivedContentEvent {
+  const DeleteHeadlineForeverRequested(this.id);
+
+  final String id;
+
+  @override
+  List<Object?> get props => [id];
+}