chore: remove ai-workflow-template submodule

[BaoT1301]

Summary

• Removes the ai-workflow-template git submodule that was accidentally committed
• Adds ai-workflow-template/ to .gitignore so it won't be re-added

Why

The submodule was not intentional — it was accidentally included in a previous PR and merged to main.

[github-actions]

🤖 Qwen Code Review

## Summary of Changes

This PR removes the `ai-workflow-template` submodule and updates the `.gitignore` file to ignore the `ai-workflow-template` directory within the `.agents/` folder.

### Highlights

* **Submodule Removal**: The `ai-workflow-template` submodule has been removed from the repository.
* **Git Ignore Update**: The `.gitignore` file has been updated to ignore the `ai-workflow-template` directory under `.agents/`.

### Changelog

* **.gitignore**
  * Added `# .agents/ai-workflow-template/` to ignore the ai-workflow-template directory.
* **ai-workflow-template**
  * Deleted the submodule entry.

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Automated review by Qwen AI

[github-actions]

🤖 Qwen Code Review

## Summary of Changes

This PR removes the `ai-workflow-template` submodule and updates the `.gitignore` file to exclude the `ai-workflow-template` directory within the `.agents/` folder.

### Highlights

* **Submodule Removal**: The `ai-workflow-template` submodule has been deleted from the repository.
* **Git Ignore Update**: The `.gitignore` file has been updated to ignore the `ai-workflow-template` directory under `.agents/`.

### Code Review

The changes appear straightforward and correctly implement the removal of the submodule and update the ignore rules. No issues found.

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Automated review by Qwen AI