SDK RELEASE V0.8.0

What's New in v0.8.0
This major release introduces Circle Gateway Nanopayments to the Python SDK, giving AI agents true high-frequency, gas-free financial autonomy.

• x402 Auto-Negotiation: nanopay() automatically resolves 402 Payment Required headers on premium URLs.
• Zero-Gas Microtransactions: EIP-3009 offline signatures allow payments as low as $0.000001 with zero blockchain latency.
• Smart Auto-Refill: Inline wallet logic automatically deposits USDC to the Gateway when funds run low.