Pusher.Send now returns the upstream response body alongside the error,
so the push task handler can print what the webhook actually replied
(custom channel e.g. {"errcode":0,"errmsg":"ok"} or a rejection
like {"errcode":93000,...}) into the task log on both success and
failure. Other pushers (lark/telegram/email) return an empty string,
keeping their behavior unchanged.
fix(push): surface webhook business errors in custom channel audit
CustomPusher.Send only checked the HTTP status code. WeChat Work /
DingTalk webhooks return HTTP 200 with a non-zero errcode in the body
even when the message is rejected (e.g. template_card requires
card_action.url when type=1), so rejected pushes were recorded as
'success' in the notification history. Parse the response body and
return an error when errcode is non-zero, matching the Lark pusher.
ryan