PERF.48 Website: ordinary Library page views read every published item (publicStats, LanguageNames::inUse, makers, forUser without LIMIT, a 652 KB cache per page)

LibraryItems::publicStats (LibraryItems.php:278-295) pulls every published row with its author and version into PHP to count authors and categories: 42 ms per view of /library and /library/author. LanguageNames::inUse (LanguageNames.php:77-83) joins all items to their versions (a UNION with addon_listings) on every Library page to learn that two languages exist: 28 to 44 ms. LibraryItems::makers (:268) SELECT DISTINCT maker over all published rows per browse page (fast today, linear later). LibraryItems::forUser (:221) has no LIMIT: the system account's /library/mine loads 13,844 rows. LibraryMetrics::totals is cached, but the cache file is 652 KB of JSON decoded on every card page (that is the 367 ms "PHP" of /library/browse). Fix: publicStats as one GROUP BY or Cache::remember 600 s with the key dropped in LibraryItems::refresh; cache inUse and makers the same way (or compute inUse in the seed); forUser paged by 50 like LibrarySubmissions::forUser; metrics labels read the per-ref rows (idx_ref) for the 48 refs on the page instead of the whole totals file. At 1 M items each of these is seconds; with the fix they are constant.