- pact.NavigationItem gains Visible func(ctx) bool (json:"-"); nil keeps the
entry always listed
- cabana.Registry.Metadata runs it after the permission check, drops a main
item (with its side menu) or a side item that answers false, and relinks a
parent whose controller is a hidden child's to its first visible openable
child
- TestNavigationHidesInvisibleItemsAndRepointsTarget covers the rules
- pact and cabana READMEs, users-and-permissions and admin-controllers docs
describe the hook
