Slack Channel Monitor

Create a cron automation that polls up to 10 Slack channels every minute. When a message containing the trigger phrase (default: @openhands) is detected it:

1. Adds a 👀 reaction to the triggering message.
2. Opens an OpenHands conversation with the message and recent channel context.
3. Posts a reply in the Slack thread with a link to the conversation.

On every subsequent run:

• New Slack thread replies are forwarded only when they contain the trigger phrase, so unrelated conversation in the thread is ignored.
• When the conversation finishes (or errors), the agent's final response is posted back to the Slack thread.
• Completed conversations stay in a short follow-up watch window, allowing triggered Slack replies to continue the same OpenHands conversation.