Fixes#31432
- Added campaign target cleanup: Deletes targets from campaigns
completed >24h ago. Uses 10% or 50k min per run, processes in 10k
batches. Added DB index, integrated into hourly cron, includes tests.
# Checklist for submitter
If some of the following don't apply, delete the relevant line.
- [x] Changes file added for user-visible changes in `changes/`,
`orbit/changes/` or `ee/fleetd-chrome/changes`.
See [Changes
files](https://github.com/fleetdm/fleet/blob/main/docs/Contributing/guides/committing-changes.md#changes-files)
for more information.
## 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
<!-- This is an auto-generated comment: release notes by coderabbit.ai
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## Summary by CodeRabbit
- New Features
- Automatic cleanup of live query campaign targets 24 hours after
campaign completion to reduce clutter and storage usage.
- Chores
- Added a database index to speed up live query target operations for
improved performance at scale.
- Enhanced scheduled maintenance to log cleanup counts and execution
time for better observability.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
