Function matches_stale_snapshot_fence_text 

fn matches_stale_snapshot_fence_text(err: &Error) -> bool

Liveness guard: when a fenced repair query fails with a wrapped error whose text indicates a stale snapshot fence (even when StatusCode::RequestOutdated was lost through client layers), classify it as SnapshotFenceExpired to break the retry loop and force a rebind of the fence high H.

Long-term the structured StatusCode / retry hint path should be preserved end-to-end; this text fallback is a narrow safety measure.