Revalidate the reservation before one mail attempt.

Private and no-store. Account epoch, project, installation and recorded notice evidence must remain valid. Records send intent and reserves one of 512 shared delivery attempts per UTC day in the same transaction before authorizing mail. Retries consume this same budget. Exhaustion preserves preparation and returns 429 without authorizing a send. Missing or invalid budget returns 503. Returns only catalog links still active from the committed event; the list can be empty for an unlinked change or native observation. It does not send mail or grant tool approval. After two minutes, interrupted preparation can be recovered and send intent without a receipt is eligible for uncertain recovery. Hourly maintenance performs bounded recovery. Uncertain sends are not automatically resent. Returns: { autorizado, vigias }