Implement DingTalk messaging channel using the official Stream Mode
WebSocket protocol with per-message session webhook replies.
- Add DingTalkChannel with send/listen/health_check support
- Add DingTalkConfig (client_id, client_secret, allowed_users)
- Integrate with onboard wizard, integrations registry, and channel
list/doctor commands
- Include unit tests for user allowlist rules and config serialization
- Remove unused `std::fmt::Write` import in `load_openclaw_bootstrap_files`
(eliminates compiler warning)
- Update WhatsApp integration status from ComingSoon to config-driven
(implementation exists in channels/whatsapp.rs)
- Update Email integration status from ComingSoon to config-driven
(implementation exists in channels/email_channel.rs)
- Update tests to reflect corrected integration statuses
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>