test(review): 新增 pytest 离线回归网，锁定 dwg_review 既有行为

在改动审查流水线（确定性检查前置 / 结论结构化 / 证据交叉校验）之前，
先立一张离线、确定性、秒级的回归网。

- tests/fakes.py：假 LLM + 假 MCP 基座 + 响应构造器（ok_text/ok_image/err）
  + make_ctx/make_evidence，绝不触网、不读密钥
- 10 个模块共 134 用例：
  mcp_client / llm_client / cad_tools / checklist / config /
  planning / evidence / review / report / annotator
- pytest.ini（testpaths=tests）+ requirements-dev.txt + 根 conftest.py
  （sys.path + RENDER_WAIT=0 / REPORT_DIR=tmp fixture）

tests/test_report.py

@@ -0,0 +1,118 @@
+"""`dwg_review.phases.report` 单元测试。"""
+
+import json
+
+from dwg_review.phases.report import extract_issues, save_report, summarize
+from tests.fakes import FakeLlmClient, make_ctx
+
+
+def findings_fixture():
+    return [
+        {"frame": 1, "sheet": "A1", "finding": "图框1：文字重叠"},
+        {"frame": 2, "sheet": "A3", "finding": "图框2：未发现明显问题"},
+    ]
+
+
+# ---------------------------------------------------------------------------
+#  summarize
+# ---------------------------------------------------------------------------
+def test_summarize_empty_returns_message_without_llm():
+    llm = FakeLlmClient(text="不应被调用")
+    ctx = make_ctx(llm=llm)
+    out = summarize(ctx, [], log=lambda *a: None)
+    assert "未识别到可审查的图框" in out
+    assert llm.calls == []
+
+
+def test_summarize_uses_chat_text():
+    llm = FakeLlmClient(text="## 总报告")
+    ctx = make_ctx(llm=llm)
+    assert summarize(ctx, findings_fixture(), log=lambda *a: None) == "## 总报告"
+    assert len(llm.calls) == 1
+    assert "图框1" in llm.calls[0]["user"]
+
+
+def test_summarize_falls_back_to_raw_input_on_error():
+    class Boom(FakeLlmClient):
+        def chat_text(self, system, user, **kwargs):
+            raise RuntimeError("汇总炸了")
+
+    logs = []
+    ctx = make_ctx(llm=Boom())
+    out = summarize(ctx, findings_fixture(), log=logs.append)
+    assert "图框1" in out and "图框2" in out
+    assert any("汇总失败" in line for line in logs)
+
+
+# ---------------------------------------------------------------------------
+#  extract_issues
+# ---------------------------------------------------------------------------
+def test_extract_issues_empty_returns_empty_list():
+    llm = FakeLlmClient(text_script=["[]"])
+    ctx = make_ctx(llm=llm)
+    assert extract_issues(ctx, [], log=lambda *a: None) == []
+    assert llm.calls == []
+
+
+def test_extract_issues_parses_json_array():
+    payload = '[{"frame": 1, "handle": "A", "severity": "high", "message": "x"}]'
+    llm = FakeLlmClient(text_script=[payload])
+    ctx = make_ctx(llm=llm)
+    issues = extract_issues(ctx, findings_fixture(), log=lambda *a: None)
+    assert issues == [{"frame": 1, "handle": "A", "severity": "high", "message": "x"}]
+
+
+def test_extract_issues_strips_code_fence():
+    fenced = '```json\n[{"frame": 1, "message": "y"}]\n```'
+    llm = FakeLlmClient(text_script=[fenced])
+    ctx = make_ctx(llm=llm)
+    assert extract_issues(ctx, findings_fixture(), log=lambda *a: None) == [
+        {"frame": 1, "message": "y"}
+    ]
+
+
+def test_extract_issues_returns_empty_on_invalid_json():
+    logs = []
+    llm = FakeLlmClient(text_script=["这不是 JSON"])
+    ctx = make_ctx(llm=llm)
+    assert extract_issues(ctx, findings_fixture(), log=logs.append) == []
+    assert any("结构化抽取失败" in line for line in logs)
+
+
+def test_extract_issues_returns_empty_when_not_a_list():
+    llm = FakeLlmClient(text_script=['{"frame": 1}'])
+    ctx = make_ctx(llm=llm)
+    assert extract_issues(ctx, findings_fixture(), log=lambda *a: None) == []
+
+
+# ---------------------------------------------------------------------------
+#  save_report
+# ---------------------------------------------------------------------------
+def test_save_report_writes_md_and_json(tmp_reports):
+    findings = findings_fixture()
+    plan = {"frames": [{"bbox": [0, 0, 10, 10]}]}
+    issues = [{"frame": 1, "handle": "A", "message": "x"}]
+
+    md_path, json_path = save_report("# 报告", findings, plan, issues, log=lambda *a: None)
+
+    assert md_path.exists() and json_path.exists()
+    assert md_path.read_text(encoding="utf-8") == "# 报告"
+    data = json.loads(json_path.read_text(encoding="utf-8"))
+    assert data["findings"] == findings
+    assert data["issues"] == issues
+    assert data["frames"] == plan["frames"]
+    assert "generated_at" in data
+
+
+def test_save_report_issues_default_to_empty(tmp_reports):
+    _, json_path = save_report("md", findings_fixture(), {"frames": []}, log=lambda *a: None)
+    assert json.loads(json_path.read_text(encoding="utf-8"))["issues"] == []
+
+
+def test_save_report_creates_missing_directory(tmp_path, monkeypatch):
+    from dwg_review import config
+
+    target = tmp_path / "deep" / "nested"
+    monkeypatch.setattr(config, "REPORT_DIR", target)
+    save_report("md", [], {"frames": []}, log=lambda *a: None)
+    assert target.is_dir()