fix(groups): 微信群排序复刻云客+群详情去掉重复的「成员列表」字段

用户报:①群详情有成员墙后「成员列表」原始串字段重复;②排序与云客不一致。

- 排序:云客「微信群统计」真机判别=员工分组(云客员工列表序)+
  组内 chatRoomId 字符串升序——/api/groups 微信路径改 JOIN
  wechat_account 按 list_order(NULL 垫底按 owner asc)+room_id asc;
  WA 保持最近活跃优先
- 群详情:memberIds 从「其他字段」兜底区排除(成员墙已替代,不再
  以原始 wxid 串重复出现)

726 测试绿(默认排序断言更新为员工分组序)。

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

yunke-server/tests/test_api_groups.py

@@ -64,17 +64,20 @@ async def _seed(session: AsyncSession) -> None:
 
 
 async def test_default_list_returns_all_ordered_desc(make_client):
-    """No filters -> 3 groups, ordered by ``last_chat_time desc`` (nulls last)."""
+    """No filters -> 3 groups;微信排序=员工分组(list_order NULL 按 owner asc)
+    +组内 room_id 字符串升序(云客群统计同款,2026-09-10)。
+    seed 无 wechat_account 行 → list_order 全 NULL → owner 字符串序:
+    wa_owner_1 < wx_owner_1 < wx_owner_2 → [wa_room_x, room_a, room_b]。
+    """
     client = await make_client(_seed)
     r = await client.get("/api/groups")
     assert r.status_code == 200
     body = r.json()
     assert body["total"] == 3
-    # 2000, 1000, null -> [room_a, room_b, wa_room_x]
     assert [it["room_id"] for it in body["items"]] == [
+        "wa_room_x@s.whatsapp.net",
         "room_a@chatroom",
         "room_b@chatroom",
-        "wa_room_x@s.whatsapp.net",
     ]
     for key in (
         "room_id",