feat(api): GET /api/moments 朋友圈列表(desc分页+账号头部)

对齐云客员工聊天窗口朋友圈tab:帖子 create_time desc 分页 +
wechat_account 头部(昵称/头像/别名);员工不存在不404(header全None
前端兜底)。头像提取抽共享 helper account_avatar 放 organization.py,
accounts 列表与 moments 头部复用。

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

yunke-server/app/api/routers/organization.py

@@ -35,6 +35,16 @@ PageParam = Annotated[int, Query(ge=1)]
 PageSizeParam = Annotated[int, Query(ge=1, le=100)]
 
 
+def account_avatar(raw_json: dict | None) -> str | None:
+    """从账号原始记录提取头像 URL(共享 helper,2026-08-25)。
+
+    WeChat ``wxUser/list`` 记录携带 ``headImageUrl``;WA ``businessSalesList``
+    记录无该键 → ``None``。accounts 列表与 moments 头部等多处复用,
+    避免同键提取散落各处。
+    """
+    return (raw_json or {}).get("headImageUrl")
+
+
 @router.get("/departments")
 async def list_departments(session: SessionDep) -> list[DepartmentOut]:
     """Return every department ordered by ``path`` (nulls last).
@@ -177,7 +187,7 @@ async def list_accounts(
             is_on_job=row.is_on_job,
             # 头像从原始记录提取(对齐云客员工聊天窗口左侧头像,2026-08-25):
             # WeChat headImageUrl;WA 原始记录无该键 -> None
-            avatar=(row.raw_json or {}).get("headImageUrl"),
+            avatar=account_avatar(row.raw_json),
             raw_json=row.raw_json,
         )
         for row in rows