Function sync_recents 

pub fn sync_recents(dir: &Path, recents: &Recents) -> bool

Regenerate the home’s recent-walks veils (recent: portals) from the traveler’s Recents — the eastern arc, freshest nearest the front door. Mirrors sync_veils’s contract: only recent: portals are touched, and places already reachable through another home veil (a starred world, the front door) are skipped rather than doubled.