Gateway-neutral, webhook-authoritative payments for WrNexus. Amounts are integer minor units. Every initialize and refund operation requires an idempotency key. The package never accepts or stores card numbers, CVVs, or expiry input; its components navigate to provider-hosted checkout.

Built-in adapters: offline sandbox, Stripe, Razorpay, and PayPal. Applications may add adapters with defineGateway. Capabilities are explicit, unsupported operations are refused, signed webhooks are mandatory in production, and package-owned migrations provision the append-only event ledger.