fix: parse WhatsApp lastUpdate datetime string to ms epoch

WA list endpoints return wall-clock strings ('2026-08-01 16:39') for
lastUpdate; storing raw broke CustomerOut.last_chat_time (int) validation
-> 500 on /api/customers?channel=whatsapp. Now parsed via parse_datetime_to_ms.

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

yunke-server/app/scraper/whatsapp.py

@@ -33,7 +33,7 @@ from collections.abc import AsyncIterator
 from typing import Any
 
 from app.scraper.base import paginate_by_cursor, paginate_by_page
-from app.scraper.parsers import coerce_int_or_none, normalize_whatsapp_type
+from app.scraper.parsers import coerce_int_or_none, normalize_whatsapp_type, parse_datetime_to_ms
 from app.session.yunke_client import YunkeClient
 
 __all__ = [
@@ -44,6 +44,10 @@ __all__ = [
 
 WHATSAPP_ACCOUNTS_PATH = "/qqweb/WhatsAppUser/businessSalesList"
 WHATSAPP_FRIENDS_PATH = "/qqweb/WhatsAppUser/businessFriendList"
+
+# WhatsApp list endpoints return wall-clock strings like "2026-08-01 16:39"
+# (no seconds) for lastUpdate/createTime — parse to ms epoch (naive UTC).
+_WA_DATETIME_FORMATS = ["%Y-%m-%d %H:%M", "%Y-%m-%d %H:%M:%S"]
 WHATSAPP_MESSAGES_PATH = "/qqweb/WhatsAppUser/chatRecords"
 
 
@@ -121,7 +125,7 @@ def _normalize_whatsapp_account(record: dict[str, Any]) -> dict[str, Any]:
         "talker_count": record.get("talkerCount"),
         "friend_add_num": record.get("friendAddNum"),
         "is_on_job": record.get("isOnJob"),
-        "last_update": record.get("lastUpdate"),
+        "last_update": parse_datetime_to_ms(record.get("lastUpdate"), _WA_DATETIME_FORMATS),
         "version": record.get("version"),
         "raw_json": record,
     }
@@ -254,7 +258,7 @@ def _normalize_whatsapp_friend(record: dict[str, Any]) -> dict[str, Any]:
         "sale_name": record.get("salesNickName"),
         "user_id": record.get("userId"),
         "message_count": record.get("messageCount"),
-        "last_chat_time": record.get("lastUpdate"),
+        "last_chat_time": parse_datetime_to_ms(record.get("lastUpdate"), _WA_DATETIME_FORMATS),
         "version": record.get("version"),
         "raw_json": record,
     }