06-workshops - [Bug] 07-Guardrails in Policy: Lab fails entirely in us-west-2 — no region guidance

**In which component is this bug present?**

- [ ] 01-AgentCore-runtime
- [x] 02-AgentCore-gateway
- [ ] 03-AgentCore-identity
- [ ] 04-AgentCore-memory
- [ ] 05-AgentCore-tools
- [ ] 06-AgentCore-observability
- [ ] 07-AgentCore-E2E

**Bug Description**

File: `deploy.py` (no region guidance)

Symptom:
```
botocore.errorfactory.AccessDeniedException: An error occurred (AccessDeniedException)
when calling the CreatePolicy operation: Guardrails policies are not enabled for this account.
```

Root Cause: The lab runs in the user's default region (us-west-2), but guardrails-in-policy is only available in select regions per the docs. Supported: us-east-1, eu-west-2, eu-north-1, ap-southeast-2, ap-northeast-1. **Not supported: us-west-2 (Oregon).**

**Suggested Fix**
Add a region check at the top of `deploy.py` that warns if the selected region doesn't support guardrails, and update the README to specify `--region us-east-1`.