List project subscription charges

Lists the verified organization's project subscription charges: the payment provider's invoices for its project subscription, read by authenticated provider call, most recent first and at most 24. Execution-credit purchases are not listed here; billing.funding reports them. Draft and zero-amount invoices are omitted. Each amount is the invoice total including tax, and the receipt link, when present, is the provider-hosted invoice page. An organization that has never been billed has an empty list; reading it creates nothing and changes nothing.