Payment links

The legacy/account-only payment-link endpoint, why it is immediately payable, and why it is excluded from the AI action schema.

Payment links remain implemented at POST /api/v1/payment-links, but they are legacy/account-only. They create an immediately payable invoice from a merchant API key, destination wallet, amount, and token. The destination wallet is trusted inline and is not pre-verified.

Because payment links return payUrl and x402Url immediately, they are not safe as general AI-assistant actions and are intentionally excluded from /.well-known/openapi.json. Prefer invoice intents for AI-created invoices.