Merge Agent Handler Adds Stripe Link Wallet

This is a meaningful step toward practical agentic commerce, but the beta label and regional limits show that payment autonomy is still entering its infrastructure phase.

• –Merge customers can add agent payments without building Link authentication and spend-request flows from scratch.
• –Scoped credentials reduce the risk of exposing reusable card details to agent runtimes.
• –Link supports virtual cards, Link Pay Tokens, and Shared Payment Tokens for different checkout environments. [Link CLI](https://github.com/stripe/link-cli)
• –User approval, merchant context, and spending limits provide important trust controls, though refunds, fraud handling, and failed payments remain implementation concerns.
• –Availability is currently limited to US and Canadian Link accounts, making this promising but not yet universally deployable. [Link FAQ](https://docs.link.com/faq)