fix: tag feed returns full FeedEntry with author and counts

crates/domain/src/testing.rs

@@ -287,6 +287,9 @@ pub struct TestStore {
     async fn search(&self, _q: &str, _p: &PageParams, _v: Option<&UserId>) -> Result<Paginated<FeedEntry>, DomainError> {
         Ok(Paginated { items: vec![], total: 0, page: 1, per_page: 20 })
     }
+    async fn tag_feed(&self, _tag_name: &str, _page: &PageParams, _viewer_id: Option<&UserId>) -> Result<Paginated<FeedEntry>, DomainError> {
+        Ok(Paginated { items: vec![], total: 0, page: 1, per_page: 20 })
+    }
 }
 
 #[async_trait] impl SearchPort for TestStore {