## Summary Rollout issue for the `use_oldrev_for_approval_reset` feature flag introduced in !228050. This flag controls whether `ResetApprovalsService` uses `push.oldrev` (captured at enqueue time) instead of the positional `previous_diff` query to determine which code owner files changed since the last push. This fixes a race condition where concurrent diff creation shifts `previous_diff`, causing code owner approvals to survive when they should be removed. ## What does the feature flag do? When **enabled**: `oldrev` from the git push hook is passed through the worker and used as the stable SHA for CODEOWNERS comparison. The 10-second `perform_in` delay is also removed (`perform_async`). When **disabled**: Falls back to the existing `previous_diff` positional query behavior (with the 10-second delay). ## Owners - Team: `group::source code` - Feature flag: `use_oldrev_for_approval_reset` - MR: !228050