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_cad_tools.py

@@ -0,0 +1,102 @@
+"""`dwg_review.cad_tools` 单元测试。"""
+
+from dwg_review.cad_tools import CadTools, is_write_tool
+from dwg_review.mcp_client import result_json
+from tests.fakes import FakeMcpClient, ok_text, tool_schema
+
+
+# ---------------------------------------------------------------------------
+#  写类工具判定
+# ---------------------------------------------------------------------------
+def test_write_prefixes_detected():
+    for name in ("add_leader_annotation", "delete_entities", "draw_line", "set_layer"):
+        assert is_write_tool(name) is True
+
+
+def test_write_exact_names_detected():
+    assert is_write_tool("set_entity_properties") is True
+    assert is_write_tool("highlight_entities") is True
+
+
+def test_readonly_tools_are_not_write():
+    for name in ("query_entities", "get_text_content", "zoom_to_window", "find_zero_length"):
+        assert is_write_tool(name) is False
+
+
+# ---------------------------------------------------------------------------
+#  注册表
+# ---------------------------------------------------------------------------
+def test_registry_built_from_client():
+    client = FakeMcpClient()
+    tools = CadTools(client)
+    assert "query_entities" in tools.names
+    assert tools.has("get_viewport_screenshot") is True
+    assert tools.has("__nope__") is False
+    assert tools.names == sorted(tools.names)
+
+
+def test_describe_returns_tool_dict():
+    client = FakeMcpClient()
+    tools = CadTools(client)
+    desc = tools.describe("query_entities")
+    assert desc["name"] == "query_entities"
+    assert "inputSchema" in desc
+
+
+def test_refresh_picks_up_new_tools():
+    client = FakeMcpClient(tools=[tool_schema("a")])
+    tools = CadTools(client)
+    assert tools.names == ["a"]
+    client._tools = [tool_schema("a"), tool_schema("b")]
+    tools.refresh()
+    assert tools.names == ["a", "b"]
+
+
+# ---------------------------------------------------------------------------
+#  openai_tools
+# ---------------------------------------------------------------------------
+def test_openai_tools_format():
+    client = FakeMcpClient(tools=[tool_schema("query_entities", "查询", {"window": {"type": "object"}})])
+    entry = CadTools(client).openai_tools()[0]
+    assert entry["type"] == "function"
+    assert entry["function"]["name"] == "query_entities"
+    assert entry["function"]["description"] == "查询"
+    assert entry["function"]["parameters"]["properties"] == {"window": {"type": "object"}}
+
+
+def test_openai_tools_defaults_schema_when_missing():
+    client = FakeMcpClient(tools=[{"name": "bare", "description": ""}])
+    entry = CadTools(client).openai_tools()[0]
+    assert entry["function"]["parameters"] == {"type": "object", "properties": {}}
+
+
+def test_openai_tools_names_filter():
+    client = FakeMcpClient()
+    names = CadTools(client).openai_tools(names={"query_entities", "get_layers"})
+    assert sorted(n["function"]["name"] for n in names) == ["get_layers", "query_entities"]
+
+
+# ---------------------------------------------------------------------------
+#  call
+# ---------------------------------------------------------------------------
+def test_call_returns_normalized_response():
+    client = FakeMcpClient(responses={"query_entities": ok_text({"total": 7})})
+    tools = CadTools(client)
+    assert result_json(tools.call("query_entities", {"window": {}})) == {"total": 7}
+    assert client.calls[-1]["name"] == "query_entities"
+    assert client.calls[-1]["arguments"] == {"window": {}}
+
+
+def test_call_marks_write_tools():
+    client = FakeMcpClient()
+    tools = CadTools(client)
+    tools.call("add_leader_annotation", {"text": "x"})
+    tools.call("query_entities", {"window": {}})
+    assert client.calls[0]["is_write"] is True
+    assert client.calls[1]["is_write"] is False
+
+
+def test_call_explicit_is_write_overrides_inference():
+    client = FakeMcpClient()
+    CadTools(client).call("query_entities", {}, is_write=True)
+    assert client.calls[-1]["is_write"] is True