fix: route None/degraded diagnoses to lapse; abort on high degrade rate

tests/unit/test_diagnose.py

@@ -17,6 +17,7 @@ from unittest.mock import AsyncMock, MagicMock
 import pytest
 
 from core.evolution.diagnose import (
+    _build_skill_case_packs,
     _percentile,
     _trigrams,
     aggregate_d2,
@@ -43,6 +44,7 @@ from core.evolution.types import (
     CaseSample,
     DiagnosePrompts,
     DiagnosisResult,
+    ErrorAttribution,
     QuestionMetrics,
     SkillStepAdherence,
     SpanMetrics,
@@ -771,3 +773,52 @@ class TestRunDiagnosis:
         assert result.run_id == "run1"
         assert result.error_attributions == []
         assert result.degraded_count == 0
+
+
+class TestBuildSkillCasePacksDegradeRouting:
+    """_build_skill_case_packs 降级/未判定分流：仅 defect 且非 degraded 进正文路径。"""
+
+    def test_none_cause_and_degraded_route_to_lapse(self) -> None:
+        """cause_category=None（判别失败）与 degraded 题按 lapse 处置，不进 defect 正文路径。"""
+        tt = "Action Reasoning"
+        qm_none = _make_qm(question_id="q-none", task_type=tt, correct=False, degraded=False)
+        qm_degraded = _make_qm(question_id="q-deg", task_type=tt, correct=False, degraded=True)
+        # 补两道正确题，避免退化
+        qm_ok1 = _make_qm(question_id="q-ok1", task_type=tt, correct=True)
+        qm_ok2 = _make_qm(question_id="q-ok2", task_type=tt, correct=True)
+        metrics = [qm_none, qm_degraded, qm_ok1, qm_ok2]
+
+        attributions = [
+            # 判别失败：cause_category=None
+            ErrorAttribution(
+                question_id="q-none",
+                error_type="reasoning",
+                reasoning_failure_type=None,
+                cause_category=None,
+                lapse_note="复核该类推理规则",
+            ),
+            # degraded 题即便被判 defect，也须走 lapse（不驱动正文进化）
+            ErrorAttribution(
+                question_id="q-deg",
+                error_type="reasoning",
+                reasoning_failure_type=None,
+                cause_category="defect",
+                lapse_note=None,
+            ),
+        ]
+
+        packs = _build_skill_case_packs(
+            all_metrics=metrics,
+            error_attributions=attributions,
+            traces_by_question={},
+            predictions=[],
+            d3_stats={},
+            d4_stats={},
+        )
+
+        pack = packs[tt]
+        failure_ids = {c.question_id for c in pack.failure_cases}
+        assert "q-none" not in failure_ids
+        assert "q-deg" not in failure_ids
+        # None-cause 的 lapse_note 应被收进 lapse_notes
+        assert any("复核该类推理规则" in n for n in pack.lapse_notes)

tests/unit/test_runner_diag_tree_inject.py

@@ -212,6 +212,32 @@ async def test_diagnosis_reads_traces_from_steps_json(
     assert traces[0]["tool_name"] == "search_tree"
 
 
+@pytest.mark.asyncio
+async def test_run_step_aborts_on_high_degrade_rate(
+    runner_with_real_store: Runner, monkeypatch: pytest.MonkeyPatch
+) -> None:
+    """诊断降级占比 > 50% 时 _run_step 中止（疑似 judge 基础设施故障）。"""
+    from unittest.mock import AsyncMock
+
+    batch = [_fake_question("q1", "vA"), _fake_question("q2", "vA")]
+
+    runner_with_real_store._rollout_batch = AsyncMock()
+    monkeypatch.setattr("app.harness.runner._apply_batch_correctness", lambda *a, **k: None)
+    runner_with_real_store._run_diagnosis = AsyncMock(
+        return_value=DiagnosisResult(run_id="r", degraded_count=2)
+    )
+    runner_with_real_store._gate_batch_skills = AsyncMock()
+
+    state = MagicMock()
+    state.correctness = {"q1": False, "q2": False}
+    state.gate_cooldown = {}
+    pools = MagicMock()
+    pools.baseline_run_id = "infer_adhoc"
+
+    with pytest.raises(RuntimeError, match="降级占比"):
+        await runner_with_real_store._run_step(1, 0, 10, batch, pools, state)
+
+
 @pytest.mark.asyncio
 async def test_run_diagnosis_full_scan_loads_all_video_trees(
     runner_with_real_store: Runner,