fix: share precise scoring failure labels across API chat and exports

backend/tests/test_optimization.py

@@ -293,6 +293,30 @@ def test_pdf_html_preserves_zero_and_none():
     assert "实验（0 / 10）" in html and "模型原始分：0" in html
 
 
+@pytest.mark.parametrize("error, label", [
+    ("模型证据未关联该片段的检索目标", "模型输出校验失败"),
+    ("模型请求或JSON校验失败（ConnectError：无法连接模型端点），已重试2次", "模型连接失败"),
+    ("模型请求或JSON校验失败（模型请求超时，请稍后重试），已重试2次", "模型连接失败"),
+    ("模型请求或JSON校验失败（HTTP 429：请求限流），已重试2次", "模型请求失败"),
+    ("模型请求或JSON校验失败（ValidationError：模型返回字段不符合格式），已重试2次", "模型输出校验失败"),
+    ("后台数据处理异常", "评分失败"),
+])
+def test_score_api_and_export_share_precise_failure_labels(sqlite_db, error, label):
+    from wisegrade.exports import project_result
+    db = sqlite_db
+    item = project(db)
+    created = services.create_batch(SimpleNamespace(course_version_id=1, rubric_version_id=1), db)
+    batch = db.get(ScoringBatch, created["id"])
+    criterion = batch.rubric_snapshot["criteria"][0]
+    db.add(CriterionScore(batch_id=batch.id, project_id=item.id,
+                          criterion_id=criterion["criterion_id"], status="failed", error=error))
+    db.commit()
+    result = project_result(db, batch, item)
+    assert result["rows"][0]["status_label"] == label
+    assert f"状态：{label}" in _html_report(result, batch)
+    assert result["rows"][0]["model_score"] is None
+
+
 def test_public_reindex_uses_saved_pages(sqlite_db):
     db = sqlite_db
     doc = document(db, None, "课程资料")