fix(catalog): show a new album once in Recently Added, not once per track

Recently Added listed every newly-added track individually, so importing a
14-track album filled the whole row with that one album and buried everything
else. Both code paths that build the row had the same symptom from separate
causes:

- Online: Jellyfin's /Items/Latest defaults to GroupItems=false, returning each
  new leaf on its own. Send GroupItems=true so the server collapses children
  into the container that was added.
- Offline: the downloaded-items CTE deliberately matches leaves *and* their
  container (right for browsing, wrong here), so a downloaded album returned the
  album plus each of its tracks. Drop a leaf only when its own container is in
  the same result.

Items with no container (movies, standalone tracks) are unaffected in both
paths. The online URL is extracted into build_latest_items_endpoint so it can be
asserted without an HTTP server, matching build_favorites_endpoint.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src-tauri/src/repository/online.rs

@@ -670,6 +670,26 @@ fn build_get_items_endpoint(
     endpoint
 }
 
+/// Build the Jellyfin endpoint for a "recently added" listing.
+///
+/// `GroupItems=true` is the load-bearing parameter: Jellyfin defaults it to
+/// `false`, which returns each newly-added *leaf* separately, so importing one
+/// 14-track album pushed 14 rows into "recently added" and buried everything
+/// else. With grouping on, the server collapses children into the container
+/// that was added — an album appears once, while movies (which have no such
+/// container) are unaffected.
+///
+/// Pulled out of `get_latest_items` so the query can be asserted without an
+/// HTTP server, matching `build_favorites_endpoint`.
+fn build_latest_items_endpoint(user_id: &str, parent_id: &str, limit: Option<usize>) -> String {
+    format!(
+        "/Users/{}/Items/Latest?ParentId={}&Limit={}&GroupItems=true&Fields=BackdropImageTags,ParentBackdropImageTags,UserData",
+        user_id,
+        parent_id,
+        limit.unwrap_or(16)
+    )
+}
+
 /// Build the Jellyfin endpoint for a favourites listing.
 ///
 /// Pulled out of `get_favorites` so the query can be asserted without an HTTP
@@ -908,11 +928,7 @@ impl MediaRepository for OnlineRepository {
         parent_id: &str,
         limit: Option<usize>,
     ) -> Result<Vec<MediaItem>, RepoError> {
-        let limit_str = limit.unwrap_or(16);
-        let endpoint = format!(
-            "/Users/{}/Items/Latest?ParentId={}&Limit={}&Fields=BackdropImageTags,ParentBackdropImageTags,UserData",
-            self.user_id, parent_id, limit_str
-        );
+        let endpoint = build_latest_items_endpoint(&self.user_id, parent_id, limit);
 
         let items: Vec<JellyfinItem> = self.get_json(&endpoint).await?;
         Ok(items
@@ -2706,6 +2722,25 @@ mod tests {
         assert!(!off.contains("Filters=IsFavorite"));
     }
 
+    /// A newly-added album must arrive as one entry, not one per track.
+    ///
+    /// Jellyfin's `/Items/Latest` defaults to `GroupItems=false`, which returns
+    /// every new Audio track individually — so ripping a 14-track album filled
+    /// the whole "recently added" row with that one album. `GroupItems=true`
+    /// makes the server collapse children into their parent container.
+    #[test]
+    fn test_latest_items_endpoint_groups_children_into_containers() {
+        let endpoint = build_latest_items_endpoint("u1", "lib-1", Some(16));
+
+        assert!(
+            endpoint.contains("GroupItems=true"),
+            "latest items must be grouped so an album counts once, got: {}",
+            endpoint
+        );
+        assert!(endpoint.contains("ParentId=lib-1"));
+        assert!(endpoint.contains("Limit=16"));
+    }
+
     /// UT-099 — a Jellyfin item's `UserData` reaches `MediaItem.user_data`.
     ///
     /// Before DR-113 this mapping was hardcoded to `None`, so nothing outside