Introduce a new channel that integrates with WeCom Customer Service
(微信客服), separate from the existing self-built WeCom app channel.
- Register channel type `wechatcom_kf` in factory, app loader and const
- Add config keys for token / secret / aes_key / port / cursor dir and
the first-start history-skip switch; also expose corresponding env vars
- Implement channel, message and cursor store under channel/wechatcom_kf/
Co-authored-by: Cursor <cursoragent@cursor.com>
