Add VeraData as x402 merchant example — sanctions screening and KYB for FSI agents

## Proposed example: VeraData — LATAM compliance data via x402

### Why this fits AgentCore Payments

The AWS blog post for AgentCore Payments explicitly names **sanctions screening services** and **credit bureau queries** as canonical FSI use cases:

> "For the use cases described in this post — agents accessing premium market data feeds, **sanctions screening services**, **credit bureau queries**, and real-time analytics — AgentCore Payments removes the last integration barrier between agent intelligence and agent action."

[VeraData](https://api.veradata.dev) is the only x402-native compliance provider covering Latin American jurisdictions. It implements exactly this use case:

### What the example would demonstrate

An AgentCore-powered FSI agent that:
1. Receives task: `"Onboard Bancolombia S.A. as a counterparty"`
2. AgentCore discovers VeraData via CDP Bazaar MCP server (already indexed)
3. AgentCore pays `$0.15 USDC` automatically to `POST https://api.veradata.dev/solutions/kyb-complete-co`
4. Agent receives: `verdict: VERIFIED`, sanctions matches, registry data, PEP screening, EU AI Act Art.12 audit trail
5. Agent proceeds with onboarding or halts based on the compliance verdict

Alternative entry at `$0.01` for quick OFAC-only screening:
```
POST https://api.veradata.dev/sanctions/quick
```

### Why LATAM compliance is the right FSI example

FSI organizations with LATAM operations face mandatory screening requirements:
- **SARLAFT** (Colombia): screening required before any business relationship
- **OFAC exposure**: federal liability regardless of jurisdiction
- **EU AI Act Art.12/13**: immutable audit trail required for AI-assisted compliance decisions

VeraData addresses all three in a single x402 call.

### Technical details

**Endpoints:**
```
POST https://api.veradata.dev/sanctions/quick — $0.01 USDC (OFAC-only)
POST https://api.veradata.dev/sanctions — $0.05 USDC (OFAC+UN+EU+UK, 59k+ entries)
POST https://api.veradata.dev/solutions/kyb-complete-co — $0.15 USDC (full KYB bundle)
```

**x402 discovery:**
- `/.well-known/x402`: https://api.veradata.dev/.well-known/x402
- CDP Bazaar: already indexed at https://agentic.market/services/api-veradata-dev
- `llms.txt`: https://api.veradata.dev/llms.txt
- OpenAPI: https://api.veradata.dev/openapi.json

**Networks:** Base (`eip155:8453`) + Solana mainnet
**Trial:** `X-TRIAL: true` header — no wallet required for testing

**Response includes:**
```json
{
"verdict": "VERIFIED",
"sanctions": {"matches": [], "lists_checked": ["OFAC_SDN","UN_CONSOLIDATED","EU_CONSOLIDATED","UK_HM_TREASURY"]},
"match_confidence": {"tier": "CLEAR", "recommended_action": "PROCEED"},
"pep_screening": {"is_pep": false},
"beneficial_ownership": {"legal_representative": "..."},
"audit_aat": {
"source_class": "independently_reproducible",
"list_snapshot_hashes": {...},
"fetch_timestamp_utc": "...",
"eu_ai_act": {"art12_logged": true, "art13_compliant": true}
}
}
```

**Listed in:**
- TensorBlock/awesome-mcp-servers
- moov-io/awesome-fintech (Compliance & Sanctions section)
- jaw9c/awesome-remote-mcp-servers (PR #456 open)
- coinbase/agentkit issue #1359

Happy to provide complete code example, OpenAPI spec, or test fixtures for integration into the sample repo.

Start with the repository's existing AgentCore Payments and x402 sample entry points; no file path or test is specified in the issue. Review VeraData's /.well-known/x402 and OpenAPI links, then verify the listed POST endpoints, payment networks, and expected KYB or sanctions response. Done should be a working VeraData merchant example demonstrating discovery, payment, and compliance handling.

Written by the indexing model from the issue text.