Update from bb

[httpdss]

This pull request updates the .github/workflows/struct-generate.yaml workflow to improve flexibility and security in how STRUCT files are handled, and to ensure the workspace is clean before generating pull requests. The most important changes are grouped below.

Workflow input improvements:

• Made the struct_file and output_dir inputs optional, and updated the default value for struct_file to use a URI scheme (file://.struct.yaml) for better compatibility.

Environment and security enhancements:

• Added the GITHUB_TOKEN environment variable to the STRUCT job, allowing secure access to GitHub APIs during execution.

Workspace cleanup before PR generation:

• Added a step to remove the custom-structures directory before generating a pull request, ensuring that no residual files affect the PR creation process.

[Copilot]

Pull request overview

This PR enhances the struct-generate.yaml workflow by making inputs more flexible, improving security through token management, and ensuring clean workspace state before PR generation. The changes focus on making the workflow more robust and compatible with URI-based file references.

• Made struct_file and output_dir inputs optional with improved defaults
• Added GITHUB_TOKEN environment variable for secure GitHub API access
• Implemented cleanup of custom-structures directory before PR generation

[Copilot]

The workflow references secrets.token instead of the standard secrets.GITHUB_TOKEN. If secrets.token is not explicitly configured in the repository settings, this will be empty and the STRUCT command may fail when attempting to access GitHub APIs. Consider using secrets.GITHUB_TOKEN which is automatically provided by GitHub Actions, or document that secrets.token must be configured.