Where a bill is on its way to being paid, and what's next

stage is one of draft, awaiting_approval, ready_to_pay, scheduled, in_progress, failed, paid. next_step says what has to happen and who does it (submitter, approvers, payer, or nobody while the payment moves); you_can_act says whether the token's user can do it; waiting_on lists approvers who can act now; blockers lists what's in the way. The payment never includes bank account or routing numbers.