Cloudflare mpp-proxy adds paid API gates

This is a practical step toward agent-era billing at the transport layer, not another SaaS paywall wrapper. The interesting part is that Cloudflare is making payment enforcement feel like infrastructure instead of application logic.

• –Deploying as a Worker means teams can gate existing APIs without rewriting origins or bolting on custom billing middleware
• –The `402` flow plus 1-hour session cookie makes the experience closer to normal access control than per-request friction
• –Bot Management support is the real leverage: you can price crawlers differently from humans instead of choosing between free access and blanket blocking
• –Adoption will hinge on how quickly MPP tooling, wallets, and client support mature beyond early adopters
• –For AI developers, this is a signal that paid inference, paid retrieval, and paid content access may start converging on common edge primitives