Publish release artifacts by package version

[Volv-G]

Summary

• replace the tangle-cli-only upload step with per-package publish planning
• publish tangle-cli and/or tangle-api only when that package version is absent from PyPI
• skip already-published versions by version existence instead of comparing rebuilt artifact hashes

Context

The tangle-cli 0.1.1 publish failed twice because the release job had built both packages and uv publish --check-url considered already-published tangle-api==0.1.0 artifacts. This makes the release workflow robust for CLI-only, API-only, and combined future releases without reprocessing unchanged package versions.

No v0.1.1 re-tag is needed; this is forward-looking for future tags.

Testing

• uv run --isolated --no-project python /tmp/test_pypi_version_check.py
  • tangle-cli 0.1.1 -> skip
  • tangle-api 0.1.0 -> skip
  • tangle-cli 99.99.99 -> publish
  • tangle-api 99.99.99 -> publish
• Ran the workflow publish-plan script locally with GITHUB_OUTPUT set:
  • publish_cli=false
  • publish_api=false
• actionlint .github/workflows/release.yaml