Playlist collages aren't generated until the build job runs over a
playlist with tracks — system playlists (For-You / Discover / Songs-
like) and any newly-created playlist hit a brief window where
/api/playlists/:id/cover returns 404. ServerImage's errorWidget
already renders the visual fallback (queue_music icon over slate);
this fix just keeps cached_network_image from spamming the dev
console with HttpExceptionWithStatus stack traces.
errorListener filters 404 specifically — auth (401/403) and any
5xx still log so real connectivity / permission issues stay visible.
User-visible behavior unchanged; this is a dev-mode log hygiene fix.
bvandeusen
6efb3159d5