Versioning

• DowngradeNotAllowed

  The desired version is below the deployed version and downgrades are not enabled.

• DowngradeRequiresMigration

  A downgrade is enabled, but a version boundary it crosses declares no down actions and is irreversible.

• Fleet rollout

  Roll one version across a fleet of StageSets in ordered waves — canary a few tenants, soak, health-check, then widen, and halt the whole fleet on regression.

• InvalidVersion

  A version source or value could not be parsed as semver.

• MigrationCoverageMissing

  A major-version transition has no migration covering it, and requireMigrationCoverage is set; the version is held back.

• Rollback

  Restore the last good artifact revision when a run fails.

• Versioned migrations

  Run migrations once, when the deployed version crosses a release boundary — inline, or sourced from a Flux artifact and shared across StageSets.