fix(feed_core): pass entity ID instead of entity object

- Update HeadlineMetadataRow to use entityId instead of entity object
- Modify push context for both topicDetails and sourceDetails routes
- Ensure correct argument type (entityId) is passed to EntityDetailsPageArguments

Author: fulleni

lib/shared/widgets/feed_core/headline_tile_image_top.dart

@@ -190,7 +190,7 @@ class _HeadlineMetadataRow extends StatelessWidget {
               context.push(
                 Routes.topicDetails,
                 extra: EntityDetailsPageArguments(
-                  entity: headline.topic,
+                  entityId: headline.topic.id,
                   contentType: ContentType.topic,
                 ),
               );
@@ -214,7 +214,7 @@ class _HeadlineMetadataRow extends StatelessWidget {
               context.push(
                 Routes.sourceDetails,
                 extra: EntityDetailsPageArguments(
-                  entity: headline.source,
+                  entityId: headline.source.id,
                   contentType: ContentType.source,
                 ),
               );