feat(examples): add EUR settlement example via fiat-capable facilitator

[petteri74dev]

Summary

Adds an Express server example showing how to accept x402 payments and receive EUR via SEPA Instant. The server code is identical to the standard Express example — the only difference is the FACILITATOR_URL pointing to a facilitator that handles USDC-to-EUR conversion.

What this enables

• European sellers receive EUR in their bank account instead of USDC
• Buyers/agents pay USDC as normal — no change to client code
• Standard exact scheme, no new packages or types needed
• One env var change from an existing x402 integration

Changes

• New example: examples/typescript/servers/eur-settlement/
• Express server with two paid endpoints (/weather, /market-data)
• README explaining the facilitator swap pattern
• .env-local with FACILITATOR_URL template

No changes to existing examples, packages, or types.

Design notes

• FACILITATOR_URL is an environment variable, not hardcoded — any fiat-capable facilitator works
• In this example, AsterPay is used as one possible EUR settlement facilitator. Other facilitators can implement the same capability by supporting the same HTTP interface.

Test plan

• pnpm install resolves without errors
• pnpm dev starts the server on port 4021
• GET /weather returns 402 Payment Required
• GET /market-data returns 402 Payment Required
• Config files match express/ example conventions
• Payment flow works with x402 client SDK

[vercel]

@petteri74dev is attempting to deploy a commit to the Coinbase Team on Vercel.

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[phdargen]

Thanks for the contribution but this doesn’t add anything beyond the standard express example beyond an env var. Examples should also remain neutral and not highlight a specific project, thats what the ecosystem page is for