- Removed several deprecated ActiveSupport time methods and added new time utilities like ActiveSupport::TimeZone#standard_name; updated config for timezone preservation.
- Introduced a structured event reporting system with Rails.event, StructuredEventSubscriber, and new testing helpers for events, errors, and notifications, plus parallel testing enhancements (worker ID helper, before_fork hook, optional D...
- Enhanced caching and JSON features: cache namespace, updatable local‑cache middleware, RedisCacheStore key‑size limit and UNLINK deletion, deterministic Gzip compression, JSON options and CIDR support, and escape of JS line/paragraph sep...