Summary

Update the Python package metadata so the published openshell package better reflects the current project positioning and distribution details.

Related Issue

N/A

Changes

• update the package description to match current OpenShell positioning
• add author, keywords, source URL, and documentation URL metadata
• expand PyPI classifiers to include the package audiences, license, security/AI topics, and macOS support

Testing

• Parsed pyproject.toml successfully with uv run python -c "import tomllib, pathlib; tomllib.loads(pathlib.Path('pyproject.toml').read_text())"

Checklist

• Follows Conventional Commits
• Commits are signed off (DCO)
• Architecture docs updated (if applicable)