Merge pull request #3241 from cpkt9762/fix/configurable-task-cleanup-delay

feat(background-task): make taskCleanupDelayMs configurable

src/features/background-agent/manager.ts

@@ -2157,7 +2157,7 @@ The task was re-queued on a fallback model after a retryable failure.
         SessionCategoryRegistry.remove(task.sessionId)
       }
       log("[background-agent] Removed completed task from memory:", taskId)
-    }, TASK_CLEANUP_DELAY_MS)
+    }, this.config?.taskCleanupDelayMs ?? TASK_CLEANUP_DELAY_MS)
 
     this.completionTimers.set(taskId, timer)
   }