This patch fixes issue #16032 where the Playlists media folder ignored a user-uploaded Primary image and kept showing the generated collage. The root cause was DTO image precedence on UserView items for CollectionType.playlists. We now prefer the display parent (PlaylistsFolder) Primary image when available by clearing the UserView Primary tag and setting ParentPrimaryImageItemId/ParentPrimaryImageTag. Added tests cover both paths: parent custom image preferred, and fallback to existing UserView Primary when parent has none.
