android: the library's file stats on the cards, the artist's own plays, the thumbnail prewarm

The desktop Library's per-record file stats on the phone (library_album_stats,
one call for the whole library): FLAC 24/96 or MP3 320k badges on the cards,
the size on the list rows and the record page. The artist page's own
listening (artist_play_stats): the time played as a chip, the most played
track under "On this phone". The whole-library thumbnail warm a moment after
boot, at the cards' edge, one decode at a time behind the tiles' gate.

src/mobile/Mobile.svelte

@@ -185,6 +185,10 @@
         bindHome();
         bindImporter();
         bindShare();
+        /* the desktop's library art prewarm: every cover cut to the cards'
+           edge, one decode at a time behind the tiles' gate, a moment after
+           boot so the first screen and a restored track come first */
+        setTimeout(() => { api.libraryArtPrewarm([360]).catch(() => {}); }, 8000);
         /* the probe handle — the desktop has __soulstream for the same reason:
            tests/mobile/smoke.mjs drives the real app through it */
         window.__ss = { nav, top, go, push, back, openSheet, closeSheet, openHalf, closeHalf, player, lib, art, slsk, net, resolver, streamSong, streamCatalogAlbum, sources, api, transfers, pls, notice, importer, next, prev, toggle, seekSecs, playQueueAt, patch };