ClickHouse Hot-NVMe to Cold-ZFS/S3 Tiering: ClickHouseCalc 3-Year Compliance Dossier

<!-- /etc/clickhouse-server/config.d/storage_tiers.xml -->
<clickhouse>
  <storage_configuration>
    <disks>
      <hot_nvme><path>/var/lib/clickhouse/hot_nvme/</path></hot_nvme>
      <cold_bulk>
        <type>s3</type>
        <endpoint>https://s3-archive.internal/ch-cold/</endpoint>
        <metadata_path>/var/lib/clickhouse/disks/cold_bulk/</metadata_path>
      </cold_bulk>
    </disks>
    <policies>
      <tiered_compliance>
        <volumes>
          <hot><disk>hot_nvme</disk></hot>
          <cold><disk>cold_bulk</disk><prefer_not_to_merge>true</prefer_not_to_merge></cold>
        </volumes>
      </tiered_compliance>
    </policies>
  </storage_configuration>
</clickhouse>

-- Table TTL re-compressing after 14d & moving to cold volume after 30d:
ALTER TABLE audit.security_events
  MODIFY TTL
    event_time + INTERVAL 14 DAY RECOMPRESS CODEC(ZSTD(9)),
    event_time + INTERVAL 30 DAY TO VOLUME 'cold',
    event_time + INTERVAL 1095 DAY DELETE;