fix: harden canonical_answer_text and align decision-core signatures to spec

tests/unit/test_adversarial_filter_core.py

@@ -7,26 +7,20 @@ from app.question_gen.adversarial_filter import (
     judge_flip,
     question_hash,
 )
-from core.types import GeneratedQuestion
 
-
-def _q(qid="q1", options=("A. 蒸", "B. 炒", "C. 煮", "D. 炸"), answer="A"):
-    return GeneratedQuestion(
-        question_id=qid, video_id="v1", task_type="Action Recognition",
-        question="?", options=options, answer=answer,
-        source_nodes=("n1",), difficulty="hard",
-        sub_pattern="temporal_reasoning_failure",
-    )
+_OPTIONS = ("A. 蒸", "B. 炒", "C. 煮", "D. 炸")
 
 
 def test_question_hash_stable_and_payload_sensitive():
-    h1 = question_hash(_q())
-    h2 = question_hash(_q())
+    h1 = question_hash("?", _OPTIONS, "A")
+    h2 = question_hash("?", _OPTIONS, "A")
     assert h1 == h2
-    h3 = question_hash(_q(answer="B"))  # answer 变 → hash 变
+    h3 = question_hash("?", _OPTIONS, "B")  # answer 变 → hash 变
     assert h1 != h3
-    h4 = question_hash(_q(options=("A. 蒸", "B. 炒", "C. 煮", "D. 烤")))  # option 变 → 变
+    h4 = question_hash("?", ("A. 蒸", "B. 炒", "C. 煮", "D. 烤"), "A")  # option 变 → 变
     assert h1 != h4
+    h5 = question_hash("!", _OPTIONS, "A")  # question 变 → 变
+    assert h1 != h5
 
 
 def test_agent_config_fingerprint_changes_with_inputs():
@@ -37,14 +31,20 @@ def test_agent_config_fingerprint_changes_with_inputs():
 
 
 def test_canonical_answer_text_maps_letter_to_option_text():
-    assert canonical_answer_text(_q(), "C") == "煮"
-    assert canonical_answer_text(_q(), "c") == "煮"
+    assert canonical_answer_text(_OPTIONS, "C") == "煮"
+    assert canonical_answer_text(_OPTIONS, "c") == "煮"
 
 
 def test_canonical_answer_text_invalid_returns_none():
-    assert canonical_answer_text(_q(), "Z") is None
-    assert canonical_answer_text(_q(), "") is None
-    assert canonical_answer_text(_q(), None) is None
+    assert canonical_answer_text(_OPTIONS, "Z") is None
+    assert canonical_answer_text(_OPTIONS, "") is None
+    assert canonical_answer_text(_OPTIONS, None) is None
+
+
+def test_canonical_answer_text_invalid_inputs_return_none():
+    for bad in ["", "AB", "E", "1", " ", "AA"]:
+        assert canonical_answer_text(_OPTIONS, bad) is None, bad
+    assert canonical_answer_text(_OPTIONS, "b") == "炒"  # 合法仍工作（去前缀、大小写不敏感）
 
 
 def test_judge_flip_different_answers_passed():