fix: get_wip_tasks 解包错误 — 新增 external_serial 后 rows 变3列但解包仍是2变量

backend/app/services/dashboard_service.py

@@ -140,7 +140,7 @@ async def get_wip_tasks(db: AsyncSession, limit: int = 20) -> list[WipTask]:
     result = await db.execute(stmt)
     rows = result.all()
 
-    raw_ids = list({t.assignee_id for t, _ in rows if t.assignee_id})
+    raw_ids = list({t.assignee_id for t, *_ in rows if t.assignee_id})
     name_map: dict[str, str] = {}
     if raw_ids:
         from app.services.mom_cache import get_display_names