Backlog: x402 agent payments tutorial (exploration)

Source: DevEx Sync (Notion).

**Status: backlog · exploration phase. Not urgent.**

Idea surfaced at the DevEx Sync — once x402-style agent payments are far enough along on Miden, write a tutorial covering the end-to-end flow: an agent submitting a payment-authorized request, the verifier checking the proof, settlement on-chain.

Scope when picked up:
- Match the shape of the existing Miden Bank / web-client tutorials.
- Cover the agent → server handshake and the on-chain settlement leg.
- Reference whichever crate(s) ship the x402 primitives (TBD — pending the protocol/client team's scoping).

Don't action until x402 has a stable surface to document.