Fix roles and payment handles after the invite.
Household page → pencil on a member card. Edit their role (co-owner, member, viewer) or payment handles anytime. The Owner role can't be changed — ownership transfer isn't supported yet.
Role and payment handles (Venmo, PayPal.Me). Members can update their own handles; role and email changes are owner-only.
Co-owner has full access — edit any bill, settle up, invite others. Member handles day-to-day logging. Viewer is read-only, for the kid's laptop or the accountant.
The owner role is assigned when the household is created and can't be edited — the server rejects the change outright. Transferring ownership isn't supported yet; if you need it, contact support.