Function reroute_preview_excluding 

pub fn reroute_preview_excluding(
    waypoints: &[Waypoint],
    geometry: &mut RouteGeometry,
    ends: Endpoints,
    excluded: &HashSet<PathOrdinal>,
    router: &mut ClosedRouter,
) -> Resolution

Non-destructive closed-router reroute: route through the stored waypoint skeleton minus excluded (a trim or prune the preview previews without applying — see PreviewExclusions in the routing module), additionally skipping inaccessible and position-duplicated corners on a working copy. The authored route is never touched (locks included: they only matter to commit-time trims, never to routing). Replaces geometry wholesale and applies the new edges’ occupancy to the router in place.