Kubernetes CronJob Transactional Email with Rovela (2026): Five-Field Schedule + Secret Env + Idempotency-Key per Window
Wire Kubernetes CronJob (batch/v1, five-field cron + timeZone) to Rovela POST /emails: Secret/secretKeyRef for sending_access, Job Pod start→exit, and a window-scoped Idempotency-Key so retries never duplicate digests.