• perf: cloneInstance() no longer inherits preload. loadResources() adds every preload language to each load, and clones copied preload from the parent, so a clone's init() and every changeLanguage() walked all preloaded languages × all namespaces through queueLoad() / hasResourceBundle(), although the parent had already loaded them into the shared store. With i18next-http-middleware (one clone + changeLanguage() per request), 25 preloaded languages and 20 namespaces, that was most of the per-request CPU: the reproduction from the issue went from ~90 µs to ~10 µs per request, the same as with a single language. A clone now only loads what it uses itself: its changeLanguage() no longer waits for parent preload languages that are still loading (the parent's own init() still does), and clone.loadNamespaces() loads the new namespace for the clone's language and fallbacks instead of every preloaded language. clone.loadLanguages() works as before, the parent instance is unchanged, and passing preload to cloneInstance() keeps the old behavior. Thanks @theMostCuriousHomunculus for the detailed report (#2451).