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/lib/mockLibrary.js

@@ -446,6 +446,7 @@ function mockCatalog(cmd, args) {
     if (cmd === "catalog_artist_profile") return Promise.resolve({ listeners: 3_100_000, plays: 210_000_000, tags: ["electronic", "house", "french house", "dance"] });
     if (cmd === "catalog_artist_bio") return Promise.resolve("Daft Punk were a French electronic music duo formed in Paris in 1993 by Guy-Manuel de Homem-Christo and Thomas Bangalter. They achieved popularity in the late 1990s as part of the French house movement.");
     if (cmd === "catalog_related") return Promise.resolve(RELATED);
+    if (cmd === "artist_play_stats") return Promise.resolve({ seconds: 7380, last_played_at: Math.floor(Date.now() / 1000) - 86400, top_title: "Track 1", top_count: 12 });
     if (cmd === "followed_artists") return Promise.resolve(follows.slice());
     if (cmd === "follow_artist") { follows.push({ artist_id: args?.artistId, name: args?.name, portrait: args?.portrait ?? null, followed_at: Date.now() / 1000 }); later(30, () => mockEmit("soulseek:follows-changed", {})); return Promise.resolve(); }
     if (cmd === "unfollow_artist") { follows = follows.filter((f) => f.artist_id !== args?.artistId); later(30, () => mockEmit("soulseek:follows-changed", {})); return Promise.resolve(); }
@@ -483,6 +484,7 @@ function mockCatalog(cmd, args) {
     }
     if (cmd === "cancel_download") return Promise.resolve();
     if (cmd === "rescan_library") return Promise.resolve();
+    if (cmd === "library_art_prewarm") return Promise.resolve();
     if (cmd === "refresh_all_album_art") return new Promise((r) => setTimeout(() => r(140), 300));
     if (cmd === "catalog_art") return Promise.resolve(svgArt(200, "D"));
     if (cmd === "stream_cache_ready") return Promise.resolve(cacheReady.has(args?.path) || (xfer && xfer.path === args?.path && xfer.received >= xfer.total));