PRD: post-send bookkeeping and terminal failure handling for the message machine

[cgrpa]

Parent

cgrpa/TheSexy6BotWorker#41

What to build

Add the final success and failure behavior for the per-message machine. After Discord delivery is confirmed, the machine should enter a post-send stage that commits session history, counters, image markers, and status updates. If anything fails during the turn, the machine should end in a generic terminal failed state that keeps the exception available for logging.

This slice covers the commit point for successful turns and the terminal failure path for unsuccessful ones.

Acceptance criteria

• Post-send bookkeeping runs only after confirmed Discord delivery.
• Successful turns commit the response payload into session history and related bookkeeping.
• The machine ends in a terminal failed state on error.
• The failure context keeps the exception available for logging.

Blocked by

• cgrpa/TheSexy6BotWorker#43
• cgrpa/TheSexy6BotWorker#44
• cgrpa/TheSexy6BotWorker#45