Make client stream writing concurrent with component streaming

Previously, chunks were written to the response stream only after all
component streaming tasks completed. Now the writer task starts
immediately and writes chunks concurrently as they arrive in the queue.

This improves streaming performance by eliminating the delay between
chunk production and delivery to the client.

Changes:
- Start writer task before waiting for barrier
- Writer dequeues and writes chunks concurrently with producers
- Added debug logging for development troubleshooting
- Disabled prerender_caching in dummy config for testing

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: AbanoubGhadban

react_on_rails_pro/lib/react_on_rails_pro/concerns/stream.rb

@@ -35,7 +35,7 @@ def stream_view_containing_react_components(template:, close_stream_at_end: true
       require "async/barrier"
       require "async/limited_queue"
 
-      Sync do
+      Sync do |parent_task|
         # Initialize async primitives for concurrent component streaming
         @async_barrier = Async::Barrier.new
         buffer_size = ReactOnRailsPro.configuration.concurrent_component_streaming_buffer_size
@@ -49,7 +49,7 @@ def stream_view_containing_react_components(template:, close_stream_at_end: true
         response.stream.write(template_string)
 
         begin
-          drain_streams_concurrently
+          drain_streams_concurrently(parent_task)
         ensure
           response.stream.close if close_stream_at_end
         end
@@ -58,17 +58,20 @@ def stream_view_containing_react_components(template:, close_stream_at_end: true
 
     private
 
-    def drain_streams_concurrently
+    def drain_streams_concurrently(parent_task)
+      writing_task = parent_task.async do
+        # Drain all remaining chunks from the queue to the response stream
+        while (chunk = @main_output_queue.dequeue)
+          response.stream.write(chunk)
+        end
+      end
+
       # Wait for all component streaming tasks to complete
       @async_barrier.wait
 
       # Close the queue to signal end of streaming
       @main_output_queue.close
-
-      # Drain all remaining chunks from the queue to the response stream
-      while (chunk = @main_output_queue.dequeue)
-        response.stream.write(chunk)
-      end
+      writing_task.wait
     end
   end
 end