Record history: attribution, batches and retention — Retention

History is kept for 24 months by default, changeable in Settings, or set to keep forever. A nightly pass enforces it, on the same schedule that already prunes automation runs and webhook deliveries. It is a duration rather than a cap on rows deliberately: "the last 500 changes" cannot answer whether a value was different in March, which is the question people actually bring to a history. History that was never captured cannot be recovered and there is no backfill, so the default errs long. Shortening it takes effect on the next nightly pass.