feat(qt): opt-in "feat." featured artists on the track-row artist line

Settings > Appearance > Player & Visuals. Qobuz rows only; the artist line
stays a single text so the artist link keeps its hit area.

cc

crates/qbz-qt/qml/settings/AppearanceSettings.qml

@@ -326,6 +326,14 @@ Column {
             onToggled: function (v) { QbzBridge.settingsBool("play-indicator-animation", v) }
         }
     }
+    SettingRow { kioskHost: root.kioskHost;
+        label: QbzSession.tr("Show featured artists in track rows", QbzSession.trRev)
+        description: QbzSession.tr("Append \"feat. …\" with the track's featured performers to the artist line of Qobuz track rows. Off by default.", QbzSession.trRev)
+        QbzToggle { kioskHost: root.kioskHost;
+            checked: root.doc.showFeaturedArtists === true
+            onToggled: function (v) { QbzBridge.settingsBool("show-featured-artists", v) }
+        }
+    }
     SettingRow { kioskHost: root.kioskHost;
         // Parked for a later visual pass. Keep the preference wiring intact so
         // restoring the experiment does not require a settings migration.