Update prototype extension to 0.2.1b4

[a11smiles]

Summary

Automated index update for the az prototype extension.

• Version: 0.2.1b4
• SHA-256: c89bcdd5ec701701df6226535c4d1e4fc0004ce047f2495c3347b02911bb6679
• Download: https://github.com/Azure/az-prototype/releases/download/v0.2.1b4/prototype-0.2.1b4-py3-none-any.whl
• Source release: https://github.com/Azure/az-prototype/releases/tag/v0.2.1b4

[azure-client-tools-bot-prd]

️✔️Azure CLI Extensions Breaking Change Test

️✔️Non Breaking Changes

[azure-client-tools-bot-prd]

Hi @a11smiles,
Please write the description of changes which can be perceived by customers into HISTORY.rst.
If you want to release a new extension version, please update the version in setup.py as well.

[yonzhan]

Thank you for your contribution! We will review the pull request and get back to you soon.

[github-actions]

The git hooks are available for azure-cli and azure-cli-extensions repos. They could help you run required checks before creating the PR.

Please sync the latest code with latest dev branch (for azure-cli) or main branch (for azure-cli-extensions).
After that please run the following commands to enable git hooks:

pip install azdev --upgrade
azdev setup -c <your azure-cli repo path> -r <your azure-cli-extensions repo path>

[github-actions]

• For more info about extension versioning, please refer to Extension version schema

[Copilot]

Pull request overview

This PR performs an automated index update to publish the az prototype Azure CLI extension at version 0.2.1b4, and adds a corresponding command-to-service mapping entry.

Changes:

• Add the prototype extension entry (download URL, metadata, SHA-256) to src/index.json.
• Add az prototype to src/service_name.json and normalize formatting of the first entry.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
src/service_name.json	Adds the az prototype command mapping and aligns formatting with the rest of the file.
src/index.json	Registers the prototype extension (v0.2.1b4) with download URL, metadata, and sha256 digest.