- Replace constant() with dynamic class constant fetch (PHP 8.3)
- Add typed class constants to Worker, Application, Schedule (PHP 8.3)
- Fix proxy() re-instantiation bug with ??= caching (correctness)
- Replace Closure::fromCallable() with first-class callable syntax (PHP 8.1)
- Replace array_values() === array_values() with array_is_list() (PHP 8.1)