A cold page no longer waits on one call for everything. Three lanes run off
the artist's id the moment it is known: Popular's ranked rows
(`catalog_artist_popular`), the banner alone (`catalog_artist_hero_seed`) and
the first page of releases (`catalog_artist_overview`) — the desktop's own
staging, for the desktop's own reason, since the identity pass inside the
full page is a MusicBrainz chain behind a one-request-a-second gate. The
overview's releases hold the discography up until the exhaustive page lands
with the classified one, and never the other way round; its `popular_tracks`
are dropped, because Popular already has a ranked lane of its own. The hero
seed pays for itself twice: its first source is the hero Kyle picked on this
phone, read off the file with no network at all, so **Choose hero photo**
shows on the next visit at once instead of behind a whole catalog page — and
both lanes are forgotten with the page when a hero is set or removed, or the
old banner would answer while the new one was still being fetched.