fix: T16 verification cleanups

- golangci-lint: errcheck on resp.Body.Close in Lidarr client + revive
  unused-parameter in delete_test.go
- coverage: 2 error-branch tests added to lidarrquarantine.Service
  (DeleteFile + DeleteViaLidarr track-not-found paths) bring per-package
  coverage to 81.4% (target >=80%)
- search/tracks.test.ts: same TrackMenu name-collision fix T13 applied to
  TrackRow.test.ts — exact-string button match instead of regex

internal/lidarr/lookup_mbid.go

@@ -18,7 +18,7 @@ func (c *Client) LookupArtistByMBID(ctx context.Context, mbid string) (LidarrArt
 	if err != nil {
 		return LidarrArtist{}, err
 	}
-	defer resp.Body.Close()
+	defer func() { _ = resp.Body.Close() }()
 
 	var rows []LidarrArtist
 	if err := json.NewDecoder(resp.Body).Decode(&rows); err != nil {
@@ -41,7 +41,7 @@ func (c *Client) LookupAlbumByMBID(ctx context.Context, mbid string) (LidarrAlbu
 	if err != nil {
 		return LidarrAlbum{}, err
 	}
-	defer resp.Body.Close()
+	defer func() { _ = resp.Body.Close() }()
 
 	var rows []LidarrAlbum
 	if err := json.NewDecoder(resp.Body).Decode(&rows); err != nil {