update CHANGELOG.md

Author: ihabadham

react_on_rails_pro/CHANGELOG.md

@@ -19,6 +19,12 @@ You can find the **package** version numbers from this repo's tags and below in
 
 _Add changes in master not yet tagged._
 
+### Improved
+- Significantly improved streaming performance by processing React components concurrently instead of sequentially. This reduces latency and improves responsiveness when using `stream_view_containing_react_components`.
+
+### Added
+- Added `config.concurrent_component_streaming_buffer_size` configuration option to control the memory buffer size for concurrent component streaming (defaults to 64). This allows fine-tuning of memory usage vs. performance for streaming applications.
+
 ### Added
 
 - Added `cached_stream_react_component` helper method, similar to `cached_react_component` but for streamed components.
@@ -48,6 +54,7 @@ _Add changes in master not yet tagged._
 
 - `config.prerender_caching`, which controls caching for non-streaming components, now also controls caching for streamed components. To disable caching for an individual render, pass `internal_option(:skip_prerender_cache)`.
 - **Configuration Migration Required**: If you are using RSC features, you must move the RSC-related configurations from `ReactOnRails.configure` to `ReactOnRailsPro.configure` in your initializers. See the migration example in the [React on Rails CHANGELOG](https://github.com/shakacode/react_on_rails/blob/master/CHANGELOG.md#unreleased).
+- Added `async` gem dependency (>= 2.6) to support concurrent streaming functionality.
 
 ## [4.0.0-rc.15] - 2025-08-11