• fix(types): restore the pre-v25.10.4 ExistsFunction shape so plain arrow functions can again be assigned to ExistsFunction-typed variables (TypeScript cannot infer type predicates through multi-overload assignment). Direct i18next.exists(key) calls still narrow key to SelectorKey — the predicate is now declared inline on i18n.exists. Custom wrappers that want the narrowing can type themselves as typeof i18next.exists 2425