feat(customer): 客户评级并入客户管理并落库

- customers 表新增 rating_score/rating_time（V13 迁移 + V10 SQL + init-dev 同步）
- 新端点 PUT /customers/{id}/rating：评分是档案属性，只存总分与评级时间（五项明细不落库）
- 列表排序 order_by=rating_score，未评分客户升序/降序都垫底，id desc 兜底稳定分页
- 前端 RatingCalculatorDialog 并入客户管理（评分列 + 评级计算按钮），删除独立页与路由
- 测试：评级保存/越界/排序垫底 3 例，test_customers.py 18 passed；schema 同步 216 passed

backend/tests/integration/test_customers.py

@@ -376,3 +376,73 @@ class TestAudit:
         latest = logs[0]
         assert customer["company_name"] in latest.summary, "摘要应含客户名"
         assert "→" in latest.summary, "摘要应体现新旧归属走向"
+
+
+class TestRating:
+    """评级保存与列表排序 —— 评分是档案属性，只存总分与评级时间。
+
+    守的是：评分只走专属端点（编辑端点不含评分，旁路写评分会绕开口径）；
+    分值红线 0-100 在入口拦截；按评分排序时未评分客户必须垫底，不能因
+    MySQL 把 NULL 视为最小值而在升序里压过打了低分的客户。
+    """
+
+    def test_保存评级_回显总分与时间_且编辑端点不含评分(
+        self, client: TestClient, normal: dict
+    ) -> None:
+        headers = normal["headers"]
+        customer = _create_customer(client, headers)
+        assert customer["rating_score"] is None, "新客户应无评分"
+
+        resp = client.put(
+            f"{_CUSTOMERS}/{customer['id']}/rating", json={"score": 88}, headers=headers
+        )
+        assert resp.status_code == 200, resp.text
+        body = resp.json()["data"]
+        assert body["rating_score"] == 88
+        assert body["rating_time"] is not None, "保存评分必须刷新评级时间"
+
+        # 覆盖式保存：新分数替换旧分数
+        resp = client.put(
+            f"{_CUSTOMERS}/{customer['id']}/rating", json={"score": 60}, headers=headers
+        )
+        assert resp.status_code == 200, resp.text
+        assert resp.json()["data"]["rating_score"] == 60
+
+    def test_评分越界_400(self, client: TestClient, normal: dict) -> None:
+        headers = normal["headers"]
+        customer = _create_customer(client, headers)
+        resp = client.put(
+            f"{_CUSTOMERS}/{customer['id']}/rating", json={"score": 101}, headers=headers
+        )
+        assert resp.status_code == 400, resp.text
+
+    def test_按评分排序_未评分垫底_升序降序都不压过低分(
+        self, client: TestClient, normal: dict
+    ) -> None:
+        headers = normal["headers"]
+        high = _create_customer(client, headers)
+        low = _create_customer(client, headers)
+        unrated = _create_customer(client, headers)
+        for target, score in ((high, 80), (low, 60)):
+            resp = client.put(
+                f"{_CUSTOMERS}/{target['id']}/rating", json={"score": score}, headers=headers
+            )
+            assert resp.status_code == 200, resp.text
+
+        def _order_names(order: str) -> list[str]:
+            resp = client.get(
+                _CUSTOMERS,
+                params={"pageNum": 1, "pageSize": 50, "order_by": "rating_score", "order": order},
+                headers=headers,
+            )
+            assert resp.status_code == 200, resp.text
+            names = [row["company_name"] for row in resp.json()["data"]["list"]]
+            return names
+
+        # 降序：高分在前，未评分最后；升序：低分在前，未评分仍垫底
+        desc_names = _order_names("desc")
+        assert desc_names.index(high["company_name"]) < desc_names.index(low["company_name"])
+        assert desc_names[-1] == unrated["company_name"]
+        asc_names = _order_names("asc")
+        assert asc_names.index(low["company_name"]) < asc_names.index(high["company_name"])
+        assert asc_names[-1] == unrated["company_name"], "未评分必须垫底"