Returns the current plan tier, plan duration, plan expiry, status, Nova/wallet
credit balance, and the active subscription (if any). Used by app dashboards
to surface plan tier and remaining trial.Required scope:read_billing
{ type, duration, expiresAt, status } — plan name (e.g. Trial,
Basic, Pro), duration label (monthly/yearly), expiry timestamp
and status (active, expired, cancelled, trialing).