feat(router): add routes for archived headlines, topics, and sources

- Replace 'archivedContent' with more specific routes for content management
- Add 'archivedHeadlines', 'archivedTopics', and 'archivedSources' routes
- Update corresponding route names for each new path

Author: fulleni

lib/router/routes.dart

@@ -44,11 +44,23 @@ abstract final class Routes {
   /// The name for the content management section route.
   static const String contentManagementName = 'contentManagement';
 
-  /// The path for the archived content page.
-  static const String archivedContent = 'archived-content';
+  /// The path for the archived headlines page.
+  static const String archivedHeadlines = 'archived-headlines';
 
-  /// The name for the archived content page route.
-  static const String archivedContentName = 'archivedContent';
+  /// The name for the archived headlines page route.
+  static const String archivedHeadlinesName = 'archivedHeadlines';
+
+  /// The path for the archived topics page.
+  static const String archivedTopics = 'archived-topics';
+
+  /// The name for the archived topics page route.
+  static const String archivedTopicsName = 'archivedTopics';
+
+  /// The path for the archived sources page.
+  static const String archivedSources = 'archived-sources';
+
+  /// The name for the archived sources page route.
+  static const String archivedSourcesName = 'archivedSources';
 
   /// The path for creating a new headline.
   static const String createHeadline = 'create-headline';