- add a managed-profile card to Settings -> Shared access, between the
invitation card and the standing-state cards
- collect exactly the four fields the create route accepts, with the date
of birth genuinely optional and never derived from a year
- refresh the account payload on success, so the new record reaches the
switcher and the banner without a reload
- assert the section is reachable for an owner and refused for a Guardian
inside a profile and for an adult manager