<!-- Add the related story/sub-task/bug number, like Resolves#123, or
remove if NA -->
**Related issue:** Resolves#46790
Example live run off this branch:
https://github.com/fleetdm/fleet/actions/runs/27005120262
Example stale issue with comment:
https://github.com/fleetdm/fleet/issues/18421
- Added `@author` mention when marking issue as stale
- Refactored so that both Fleetie and eng-initiated stale issue bots use
the same core JS code
- Run Fleetie-initiated workflow on a schedule
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **New Features**
* Automated stale-issue workflows for engineering-initiated and Fleetie
issues with configurable dry-run, max-operations, manual triggers, and
scheduled runs.
* **Tests**
* Added shared test helpers and expanded, tightened test suites covering
staleness, closing, unstale, and error/boundary behaviors.
* **Refactor**
* Introduced a shared stale-issue engine used by thin,
author/label-based wrappers for consistent behavior and messaging.
* **Chores**
* Updated workflow triggers, permissions, and CI test matrix to include
the new core and wrappers.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
