fix: update test for new task message format

- test_task_scheduler_fixes.py: update assertion to match new tarea header format

Author: astrovm

tests/test_task_scheduler_fixes.py

@@ -213,7 +213,7 @@ def test_sent_message_includes_tarea_programada_prefix(self, mock_sched):
         _flush_task_pool()
 
         sent_text = mock_send.call_args[0][1]
-        assert "tarea programada:" in sent_text
+        assert "tarea «recordame algo»:" in sent_text
 
 
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