<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
- Chores
- Added automated cleanup of preview builds older than seven days to
reduce storage usage; runs on non-release pushes and won’t fail the
build if cleanup issues occur.
- Introduced a tool to optionally remove all pull request preview builds
with confirmation and clear summaries.
- Updated CI behavior to cancel in-progress runs only for pull requests;
pushes and releases are no longer auto-canceled.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
