fix(management): 评审修正——config_json注解对齐NOT NULL+补3个约束测试

- EmployeeScoreConfig.config_json 去掉 | None,注解与 DDL(nullable=False)一致
- 删测试死 import datetime as dt
- 补约束测试: metric_daily 复合PK防重/ call_daily PK防重/ config_json NOT NULL
  (JSON 列 Python None 序列化为 'null' 字符串,测 NOT NULL 须 sa.null())
- EmployeeScoreConfig docstring 补 JSON 列整列重赋值注记

Co-Authored-By: Claude Code <noreply@anthropic.com>

yunke-server/tests/test_management_models.py

@@ -3,8 +3,6 @@
 只验证:建表可用、主键/唯一约束生效、默认值正确。业务逻辑在
 first_reply_facts / employee_metrics 的测试里。
 """
-import datetime as dt  # noqa: F401
-
 import pytest
 import sqlalchemy as sa
 from sqlalchemy.exc import IntegrityError
@@ -62,6 +60,19 @@ async def test_metric_daily_defaults_zero_not_none(make_session):
     assert row.data_complete is False or row.data_complete == 0  # SQLite 0/1
 
 
+async def test_metric_daily_pk_duplicate_rejected(make_session):
+    """同 (day, channel, user_id, metric_version) 复合主键防重。
+
+    Task 6 delete+insert 幂等重算的安全网:版本内重复落表直接 IntegrityError。
+    """
+    s = make_session
+    s.add(EmployeeMetricDaily(day=20260901, channel="wechat", user_id="u1"))
+    await s.commit()
+    s.add(EmployeeMetricDaily(day=20260901, channel="wechat", user_id="u1"))
+    with pytest.raises(IntegrityError):
+        await s.commit()
+
+
 async def test_call_daily_roundtrip(make_session):
     s = make_session
     s.add(EmployeeCallDaily(day=20260901, user_id="u1", call_count=2,
@@ -72,6 +83,15 @@ async def test_call_daily_roundtrip(make_session):
     assert row.call_seconds == 164
 
 
+async def test_call_daily_pk_duplicate_rejected(make_session):
+    s = make_session
+    s.add(EmployeeCallDaily(day=20260901, user_id="u1"))
+    await s.commit()
+    s.add(EmployeeCallDaily(day=20260901, user_id="u1"))
+    with pytest.raises(IntegrityError):
+        await s.commit()
+
+
 async def test_score_config_version_unique(make_session):
     s = make_session
     s.add(EmployeeScoreConfig(version="v1.0", name="一期试算",
@@ -83,6 +103,19 @@ async def test_score_config_version_unique(make_session):
         await s.commit()
 
 
+async def test_score_config_config_json_not_null(make_session):
+    """config_json NOT NULL——注解与 DDL 一致(修复:去掉 | None)。
+
+    注意 JSON 列语义:Python None 经 JSON 序列化变成字符串 'null' 而非
+    SQL NULL,不会违反约束;测 NOT NULL 须用 sa.null() 显式发 SQL NULL。
+    """
+    s = make_session
+    s.add(EmployeeScoreConfig(version="v1.0", name="空配置",
+                              config_json=sa.null()))
+    with pytest.raises(IntegrityError):
+        await s.commit()
+
+
 async def test_snapshot_batch_user_unique(make_session):
     s = make_session
     common = {"snapshot_batch_id": "b1", "period_type": "week",