[ALNR-6808] Add standalone lbox-alignerr PyPI publish workflow

[pawelkozik-labelbox]

https://labelbox.atlassian.net/browse/ALNR-6808

Context

• lbox-alignerr 0.3.0 is on develop, but prod PyPI still only has 0.1.0
• Publishing via the reusable lbox-publish.yml path fails PyPI Trusted Publishing (OIDC cannot use reusable workflows)
• Core SDK Publish intentionally disabled build-lbox for that reason

In scope

• Add a standalone LBox Alignerr Publish workflow (workflow_dispatch) that builds and publishes only lbox-alignerr
• Require immutable tags shaped lbox-alignerr-vX.Y.Z and verify they match pyproject.toml
• Run format/lint/unit/staging integration on Python 3.9–3.13 before publish
• Publish with environment publish-lbox-alignerr (trusted publisher)

Out of scope

• Changing main labelbox SDK Publish
• Re-enabling reusable build-lbox
• Creating the release tag / running the first publish (post-merge; see PR notes)

Post-merge release steps (0.3.0)

1. On PyPI project lbox-alignerr, add Trusted Publisher:
   • Owner: Labelbox
   • Repo: labelbox-python
   • Workflow: lbox-alignerr-publish.yml
   • Environment: publish-lbox-alignerr
2. Ensure GitHub Environment publish-lbox-alignerr exists (protection rules as needed)
3. Tag and push:

   git tag lbox-alignerr-v0.3.0 33e301dd
   git push origin lbox-alignerr-v0.3.0

4. Dispatch:

   gh workflow run "LBox Alignerr Publish" -f tag=lbox-alignerr-v0.3.0

5. Verify: https://pypi.org/project/lbox-alignerr/ shows 0.3.0

---

Note

Low Risk
CI-only addition with gated publish; no runtime SDK changes, though misconfigured PyPI trusted publisher or environment could block or mis-target releases.

Overview
Adds a manual GitHub Actions workflow (lbox-alignerr-publish.yml) so lbox-alignerr can ship to PyPI without the reusable publish path that breaks Trusted Publishing (OIDC).

Operators dispatch with a release tag (lbox-alignerr-vX.Y.Z). A validate-tag job rejects bad tag shapes and requires the semver in the tag to match libs/lbox-alignerr/pyproject.toml. test runs format, lint, unit, and staging integration across Python 3.9–3.13 (staging concurrency group aligned with other LBox workflows). build produces artifacts from the tagged ref; pypi-publish uploads via pypa/gh-action-pypi-publish using the publish-lbox-alignerr environment and id-token: write.

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