Add automated release workflow and update changelog structure

[nhorton]

Summary

This PR introduces an automated release workflow that streamlines the process of creating new releases for the DeepWork project. It includes a GitHub Actions workflow that handles version validation, changelog updates, version bumping, and GitHub release creation.

Key Changes

• New GitHub Actions Workflow (create-release.yml): Implements a manual dispatch workflow that:

  • Validates version format (X.Y.Z semantic versioning)
  • Updates CHANGELOG.md with new version and maintains Unreleased section
  • Updates version in pyproject.toml
  • Regenerates lock file using uv sync
  • Creates a git commit and tag
  • Generates a GitHub Release with extracted changelog notes

• Updated CHANGELOG.md:

  • Added "Unreleased" section template at the top for tracking unreleased changes
  • Added reference links at the bottom for version comparisons
  • Maintains Keep a Changelog format

Implementation Details

• The workflow uses workflow_dispatch to allow manual triggering with a version input parameter
• Version format is validated using regex to ensure semantic versioning compliance
• Changelog processing uses awk to intelligently handle both existing and non-existing Unreleased sections
• Release notes are automatically extracted from the changelog for the GitHub Release
• Git operations are performed by the github-actions[bot] user
• The workflow requires contents: write permission to create releases and push commits

Usage

To create a release, trigger the workflow manually from the Actions tab with the desired version number (e.g., 0.6.0).