01-tutorials - [Bug]

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

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

If you are reporting multiple bugs, please create a separate issue for each. For documentation improvements, use the documentation improvement issue type.

**Bug Description**
A clear and concise description of the bug.
```
Per [model deprecation notice, the claude 3-7 model](https://docs.claude.com/en/docs/about-claude/model-deprecations#2025-10-28%3A-claude-sonnet-3-7-model) wont be available by feb, 2026. We may want to update the code samples to use the replacement models (like sonnet 4) instead to avoid errors during workshop training.

This affects a large number of modules - for an example, review amazon-bedrock-agentcore-workshop/02-AgentCore-gateway/03-search-tools/01-gateway-search.ipynb for a sample where claude 3-7 is hard-coded ("us.anthropic.claude-3-7-sonnet-20250219-v1:0").

```

**Screenshots**
If applicable, add screenshots to help explain your problem.
```
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```