Amazon Bedrock AgentCore Samples - [Bug]404 Not Found Error at 01-tutorials/06-AgentCore-observability/01 due to hidden file access restriction in JupyterLab

**Describe the bug**
While executing notebook:
`amazon-bedrock-agentcore-samples/01-tutorials/06-AgentCore-observability/01-Agentcore-runtime-hosted/runtime_with_strands_and_bedrock_models.ipynb`

The configuration step fails with `404 Not Found` error when attempting to load `.bedrock_agentcore.yaml` which is a hidden file at `Configure AgentCore Runtime deployment` Section.
That's because JupyterLab refuses to access hidden file by default. (c.ContentsManager.allow_hidden = False)

**To Reproduce**
Steps to reproduce the behavior (or some version of this):
1. Go to 'amazon-bedrock-agentcore-samples/01-tutorials/06-AgentCore-observability/01-Agentcore-runtime-hosted/runtime_with_strands_and_bedrock_models.ipynb'
2. Open the above notebook in JupyterLab
3. Run the cell under `Configure AgentCore Runtime deployment`
4. See the error
```
[E 2025-07-25 11:39:57.930 ServerApp] Uncaught exception GET /api/contents/01-tutorials/06-AgentCore-observability/01-Agentcore-runtime-hosted/.dockerignore?content=0&hash=0&1753411197920 (::1)
...
raise web.HTTPError(404, four_o_four)
tornado.web.HTTPError: HTTP 404: Not Found (file or directory does not exist: '01-tutorials/06-AgentCore-observability/01-Agentcore-runtime-hosted/.bedrock_agentcore.yaml')
...
raise RuntimeError("Cannot write() after finish()")
RuntimeError: Cannot write() after finish()
```
**Expected behavior**
The notebook should clearly inform the user to configure Jupyter Server to allow access to hidden files before attempting to load `.bedrock_agentcore.yaml`,
by
```
vi ~/.jupyter/jupyter_server_config.py
```
```
c.ContentsManager.allow_hidden = True
```
Restart JupyterLab

**Screenshots**

Open 01-tutorials/06-AgentCore-observability/01-Agentcore-runtime-hosted/runtime_with_strands_and_bedrock_models.ipynb and inspect the cell in the “Configure AgentCore Runtime deployment” section that loads .bedrock_agentcore.yaml. Reproduce the 404 in JupyterLab, then verify the notebook clearly covers the required hidden-file configuration and that the deployment cell runs successfully after restarting JupyterLab.

Written by the indexing model from the issue text.