feat(gateway): unify QQBot branding, add PLATFORM_HINTS, fix streaming, restore missing setup functions

- Rename platform from 'qq' to 'qqbot' across all integration points
  (Platform enum, toolset, config keys, import paths, file rename qq.py → qqbot.py)
- Add PLATFORM_HINTS for QQBot in prompt_builder (QQ supports markdown)
- Set SUPPORTS_MESSAGE_EDITING = False to skip streaming on QQ
  (prevents duplicate messages from non-editable partial + final sends)
- Add _send_qqbot() standalone send function for cron/send_message tool
- Add interactive _setup_qq() wizard in hermes_cli/setup.py
- Restore missing _setup_signal/email/sms/dingtalk/feishu/wecom/wecom_callback
  functions that were lost during the original merge

hermes_cli/tools_config.py

@@ -427,7 +427,7 @@ def _get_enabled_platforms() -> List[str]:
     if get_env_value("WHATSAPP_ENABLED"):
         enabled.append("whatsapp")
     if get_env_value("QQ_APP_ID"):
-        enabled.append("qq")
+        enabled.append("qqbot")
     return enabled