<!-- Add the related story/sub-task/bug number, like Resolves#123, or
remove if NA -->
**Related issue:** Resolves#43943
# Checklist for submitter
- [x] Input data is properly validated, `SELECT *` is avoided, SQL
injection is prevented (using placeholders for values in statements), JS
inline code is prevented especially for url redirects, and untrusted
data interpolated into shell scripts/commands is validated against shell
metacharacters.
## Testing
- [x] Added/updated automated tests
- [x] Where appropriate, [automated tests simulate multiple hosts and
test for host
isolation](https://github.com/fleetdm/fleet/blob/main/docs/Contributing/reference/patterns-backend.md#unit-testing)
(updates to one hosts's records do not affect another)
- [x] QA'd all new/changed functionality manually
See
https://github.com/fleetdm/fleet/issues/43943#issuecomment-4329658412
## Database migrations
- [x] Checked schema for all modified table for columns that will
auto-update timestamps during migration.
## New Fleet configuration settings
- [x] Verified that the setting is exported via `fleetctl
generate-gitops`
- [x] Verified the setting is documented in a separate PR to [the GitOps
documentation](https://github.com/fleetdm/fleet/blob/main/docs/Configuration/yaml-files.md#L485)
(see https://github.com/fleetdm/fleet/pull/43877/changes)
- [x] Verified that the setting is cleared on the server if it is not
supplied in a YAML file (or that it is documented as being optional)
- [ ] Verified that any relevant UI is disabled when GitOps mode is
enabled (should be done by
https://github.com/fleetdm/fleet/issues/43947)
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **New Features**
* Added a configuration option to preserve host activities during host
re-enrollment, letting admins choose whether activity history is
retained when hosts re-enroll.
* **Chores**
* Updated defaults and database migration state so the new setting is
present in stored and generated configs and in GitOps outputs.
* **Tests**
* Added unit, integration, migration, and GitOps fixtures to validate
behavior, serialization, and upgrade semantics.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
Martin Angers
2c609ae78e