ci: add manual PyPI trusted publishing

[saagpatel]

What

• Adds a manual Publish to PyPI workflow that builds a selected v* release tag and publishes with PyPI Trusted Publishing.
• Documents the required PyPI Trusted Publisher settings and protected pypi environment expectation.
• Extends distribution-policy tests to guard the manual-only workflow and OIDC publish permissions.

Why

• The public repo is release-ready on GitHub Releases, but PyPI should have a safe activation path before the first registry publish.
• Trusted Publishing avoids long-lived PyPI tokens and keeps publishing behind an intentional manual workflow.

How

• Uses workflow_dispatch only, validates a v* tag input, builds wheel/sdist, runs twine check, uploads distributions, then publishes from a separate pypi environment job with id-token: write.

Testing

• ruff check src/ tests/
• python3 -m pytest tests/test_distribution_policy.py tests/test_versioning.py -q -p no:cacheprovider
• python3 -m pytest -q -p no:cacheprovider
• Parsed .github/workflows/*.yml with PyYAML

Performance Impact

• None expected; workflow/docs/test-only change.

Risk / Notes

• This does not publish to PyPI by itself. PyPI still requires Trusted Publisher configuration for owner saagpatel, repository GithubRepoAuditor, workflow pypi.yml, environment pypi, plus an intentional manual run.

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: a1b54756e0

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

Avoid interpolating dispatch input into the shell

When someone who can manually run this workflow enters a ref such as v$(...), GitHub substitutes the raw workflow_dispatch input into this run script and the shell evaluates the command substitution before the case match. That lets the dispatch input execute arbitrary commands in the build job before checkout; pass the input through an environment variable and validate the variable value instead.

Useful? React with 👍 / 👎.

[chatgpt-codex-connector]

Reject non-tag refs before publishing

This check only verifies that the input starts with v, so a mutable branch named vnext or v0.1.2-fix can be selected and then built/published even though the workflow and release docs say PyPI publishes must come from release tags. Validate that the input resolves to refs/tags/<ref> before building so the protected publish job cannot publish an untagged branch by mistake.

Useful? React with 👍 / 👎.