- Added Enumerator support to ActiveSupport::SafeBuffer and enhanced Range comparison methods for beginless/endless ranges.
- Fixed numerous bugs across caching, database connections, association validations, lazy loading, memoization, and process forking behavior.
- Improved autoloading inflector overrides, updated SystemTestCase inheritance for system tests, added IE9‑compatible UJS handling, and updated .gitignore and generated .keep files for new apps.