Payout methods

Lists the available payout methods (analogous to pay-in's GET /payment-methods). Each method carries a stable numeric `payoutMethodId` (send it to POST /me/payout/send) and the same neutral numeric identifier encoded as a string in `id`, `currency`, `country`, `rail`, indicative limits, `funded` (true if you have a payout balance in that currency) + `currencyAvailable`, `logoUrl` (alias `iconUrl`) — an absolute public URL of the rail's brand icon you can render directly (`<img src={logoUrl}>`) — and `recipientFields`: the EXACT beneficiary fields to send in the payout's `recipient` for THAT method (key, label, required, type, and `options` for bank selectors — e.g. the Colombia/Peru bank list with the exact bank_code to send). Read it to build a correct payout request without guessing. New payout methods receive their numeric ID automatically when registered in the catalog. IDs are stable within this platform and never recycled on rename or disable; they are not pay-in IDs. Only methods assigned and enabled for your shop/environment are returned. An empty list means no eligible method is configured; ask your account manager. Local Currency shops use available funds in the same currency directly. USD-model shops transfer USD to Payouts and swap to the destination currency when needed. In sandbox the synthetic `sbx_po_*` test rails are prepended.