Handle a Slack interactivity payload.
Routes by action_id prefix:
action_id
mj:view_full:*
mj:action_*
The raw JSON string from the payload form field.
payload
Slack WebClient for API calls (e.g., opening modals).
Optional
Optional SlackAdapter for form round-trip (posting choices back as messages).
Handle a Slack interactivity payload.
Routes by
action_idprefix:mj:view_full:*— Opens a modal with the full agent responsemj:action_*— Custom agent action buttons (logged, no-op for now)