Deal created

Re-queues ONE of the caller's own webhook deliveries for immediate redelivery. Only terminal-failure callbacks qualify (status ERROR or RETRY); PENDING/SUCCESS reject with 400 FAILED_PRECONDITION. Rate limit: at most one manual retry per callback per 60 seconds (429 RESOURCE_EXHAUSTED otherwise). A foreign callback_id is 403, an unknown one is 404. The re-queued row returns with status PENDING, response fields cleared and retry_count PRESERVED (unlike the admin retry which resets attempts). Dual-homed: HMAC pair or cabinet JWT. Empty JSON object body.