Update doc/adr/0001_task_state_management_refactoring.md

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: jmesnil

doc/adr/0001_task_state_management_refactoring.md

@@ -17,7 +17,7 @@ We refactored the task state management to follow a two-phase approach with prop
 ### Separate State Building from Persistence
 
 **Introduced `TaskStateProcessor` for In-Memory State Management**:
-- Created per `DefaultRequestHandler` instance to maintain request handler's in-flight tasks
+- Instantiated within the `DefaultRequestHandler` singleton, making it a global, in-memory store for all in-flight tasks
 - Maintains task state in memory during event processing
 - Provides methods to build task state from events without persisting
 - Includes `removeTask()` method for explicit cleanup