cover logo: fix the two ways artists silently lost their wordmark

Both regressions were invisible because the pipeline's failure mode is a shrug:
no logo, no error, fall back to plain text.

1. The dominance guard was resolution-dependent. It bins the crop into a coarse
   16-cubed RGB histogram and rejects when the dominant colour holds under half
   the pixels ("text over a photo"). A BIGGER source resolves more grain and
   JPEG texture, which spreads pixels across bins and shrinks that share -- so
   the identical crop of Alvvays' "Blue Rev" measures dominance 0.746 at 1000px
   and 0.226 at 3000px. Once the upgrade path started supplying hi-res artwork,
   covers that had segmented cleanly for months began failing a guard that had
   not changed; its input grew. The histogram and guard now read a copy
   normalised to the 1000px they were calibrated at, while the alpha ramp still
   runs at full resolution -- which is the whole reason for fetching the larger
   cover.

2. Only the top 14 covers were ever offered. The rank puts albums first and
   penalises remix/mix/edit/live titles, but a prolific artist's wordmark is
   often on exactly those: Poolside has 74 releases and SEVEN covers that OCR
   reads as "POOLSIDE", every one of them outside a 14-cover window. The cap
   goes to 40 on both sides (the frontend list must not undercut the backend's,
   since whatever it trims the extractor can never see). This is free for
   artists that hit early -- the locate loop stops at COVER_LOGO_MAX_HITS -- and
   is paid once, then cached, by artists with no wordmark at all.

Recovered: Alvvays (nothing -> 871x173), Poolside (nothing -> 528x225),
Men I Trust, and Motor City Drum Ensemble now extracts too. Verified no
regression across the rest of the research roster: Camping in Alaska, Crazy P,
Folamour, Hot Toddy, Mildlife, Session Victim, Turnover, Knocked Loose,
Snail Mail, Spiritbox and Todd Terje all still extract at their previous sizes.

src/lib/state.svelte.js

@@ -1285,12 +1285,17 @@ function albumLogoRank(a) {
     return typeRank + noisy;
 }
 
+// Must not undercut the backend's own cap (COVER_LOGO_MAX_COVERS): whatever is
+// trimmed here the extractor can never see. A prolific artist's wordmark is
+// frequently on a low-ranked remix single — all seven of Poolside's readable
+// covers sat past position 14 — and the backend stops early once it has enough
+// hits, so a longer list costs nothing for artists whose top covers work.
 function coverLogoCandidates(page) {
     return [...(page.albums ?? [])]
         .sort((a, b) => albumLogoRank(a) - albumLogoRank(b))
         .map((a) => ({ title: a.title ?? "", url: a.cover }))
         .filter((c) => c.url)
-        .slice(0, 14);
+        .slice(0, 40);
 }
 
 function coverLogoInputKey(artistId, page, covers) {