Cash out crypto.
Ship it in one prompt.

Integrate Peer Cash into this application using the current @zkp2p/cash package.

Before changing code, read https://github.com/zkp2p/peer-cash/blob/main/AGENTS.md and inspect this repository's wallet, signing, state, and test patterns.

Requirements:
1. Install @zkp2p/cash and viem with this repository's existing package manager.
2. Use createCashClient({ environment: "production" }) and discover payment platforms and currencies with capabilities(). Do not hardcode Relay source assets.
3. Add a cash-out flow that routes a Relay-supported EVM source asset into Base USDC, then creates a fiat cash-out order. Start with the Base USDC path if the host cannot safely execute Relay routes.
4. Keep signing in the existing wallet or policy boundary. If signing happens outside the process, use prepare(), submit txs in steps[] order, wait for each receipt, then call finalizePreparedCashout().
5. Persist depositId with the current user or operation. Resume with order(depositId), and drive the UI or agent from state, nextActions, and typed CashError remediation. Never infer lifecycle state.
6. Treat estimate() as an oracle estimate, never a locked quote. Respect requiresAtomicAccessPolicy and requiresIdentityAttestation from capabilities(); fail before moving funds when the host cannot satisfy them.
7. Use withdraw(depositId) as the only unwind path. Never call escrow contracts directly or resubmit an unknown transaction.
8. Add focused tests for discovery, signing boundaries, persistence, recovery, and error handling. Run the repository's relevant test, typecheck, lint, and build commands.

Finish by reporting the files changed, the exact checks run, and any platform capability the host deliberately leaves to Peer web.