fix: evaluate_turn_regex crashes on a non-string agent_reply (#1723)

tests/test_teacher_eval_nonstring_reply.py

@@ -0,0 +1,14 @@
+from src.teacher_escalation import evaluate_turn_regex
+
+
+def test_evaluate_turn_regex_tolerates_non_string_reply():
+    # agent_reply is typed str but is the raw LLM turn output; a non-string
+    # (dict / number from a malformed turn) made pat.search(agent_reply) raise
+    # TypeError. The tool_results branch already isinstance-guards its rows.
+    assert evaluate_turn_regex([], 123) == ("ok", None)
+    assert evaluate_turn_regex([], {"text": "I cannot do that"}) == ("ok", None)
+
+
+def test_evaluate_turn_regex_still_flags_give_up_string():
+    status, _ = evaluate_turn_regex([], "I don't have a tool to do that")
+    assert status == "failure"