fix: whatsapp businessFriendList needs page+departmentId+type

Live validation: businessFriendList uses 'page' (not pageNum) and REQUIRES
departmentId (root) + type or returns empty. Same class of bug as wxUser/list.

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

yunke-server/app/scraper/whatsapp.py

@@ -203,9 +203,26 @@ def _parse_wa_friend_rows(resp: Any) -> list[dict[str, Any]]:
     return rows if isinstance(rows, list) else []
 
 
-def _build_wa_friend_body(page_num: int, page_size: int) -> dict[str, Any]:
-    """Build the ``businessFriendList`` request body for a given page."""
-    return {"pageNum": page_num, "pageSize": page_size}
+def _build_wa_friend_body(
+    page_num: int, page_size: int, *, department_id: str = ""
+) -> dict[str, Any]:
+    """Build the ``businessFriendList`` request body for a given page.
+
+    Live capture: ``{"searchInfo":"","friendSearchInfo":"","page":1,
+    "pageSize":10,"departmentId":"<root>","type":"0"}``. Note this endpoint
+    uses ``page`` (NOT ``pageNum`` like businessSalesList) and REQUIRES
+    ``departmentId`` (the company-root dept id) + ``type`` or it returns empty.
+    """
+    body: dict[str, Any] = {
+        "searchInfo": "",
+        "friendSearchInfo": "",
+        "page": page_num,
+        "pageSize": page_size,
+        "type": "0",
+    }
+    if department_id:
+        body["departmentId"] = department_id
+    return body
 
 
 def _normalize_whatsapp_friend(record: dict[str, Any]) -> dict[str, Any]:
@@ -246,6 +263,7 @@ def _normalize_whatsapp_friend(record: dict[str, Any]) -> dict[str, Any]:
 async def scrape_whatsapp_friends(
     client: YunkeClient,
     *,
+    department_id: str = "",
     page_size: int = 50,
 ) -> AsyncIterator[dict[str, Any]]:
     """Yield normalized WhatsApp contact records from ``businessFriendList``.
@@ -270,6 +288,7 @@ async def scrape_whatsapp_friends(
         parse_total=_parse_wa_friend_total,
         parse_rows=_parse_wa_friend_rows,
         build_body=_build_wa_friend_body,
+        department_id=department_id,
     ):
         yield _normalize_whatsapp_friend(record)