fix: restore controls after task completion

tests/test_background_tasks.py

@@ -56,6 +56,14 @@ def test_deferred_task_answers_are_rejected():
         "Reuters reports that the agreement was signed today, while the BBC says voting begins Monday."
     )
 
+    news_worker = TaskWorker("test", "Find the latest international news headlines")
+    assert news_worker._is_underfilled_news_answer(
+        "One flood was reported. Other sources indicate ongoing coverage of world events."
+    )
+    assert not news_worker._is_underfilled_news_answer(
+        "Nepal began flood recovery, Venezuela signed an oil agreement, and Iran resumed talks."
+    )
+
 
 def test_task_event_directories_are_isolated(tmp_path):
     first = TaskRegistry(tmp_path / "room-one")