chore: Enhance release workflow with automatic PyPI publishing

Improvements to .github/workflows/release.yml:
- Added package validation step (twine check)
- Extract version from git tag automatically
- Generate release notes from CHANGELOG.md (with fallback to git log)
- Add full changelog link to release notes
- Improved PyPI publishing with verbose output
- Only publish to PyPI on tag push (not manual workflow_dispatch)
- Added id-token permission for future trusted publishing support

How it works:
1. Push a version tag: git tag v1.6.3 && git push origin v1.6.3
2. GitHub Actions automatically:
   - Builds the package
   - Validates with twine check
   - Creates GitHub release with changelog
   - Publishes to PyPI (if PYPI_API_TOKEN secret is set)

Setup required:
- Add PYPI_API_TOKEN to GitHub repository secrets

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: GeneAI

.github/workflows/release.yml

@@ -7,10 +7,12 @@ on:
   workflow_dispatch:
 
 jobs:
-  create-release:
+  build-and-release:
     runs-on: ubuntu-latest
     permissions:
       contents: write
+      id-token: write  # Required for trusted publishing
+
     steps:
     - uses: actions/checkout@v4
       with:
@@ -29,27 +31,57 @@ jobs:
     - name: Build package
       run: python -m build
 
-    - name: Generate changelog
+    - name: Validate package
+      run: |
+        twine check dist/*
+        echo "✓ Package validation passed"
+
+    - name: Extract version from tag
+      id: version
+      run: |
+        VERSION=${GITHUB_REF#refs/tags/v}
+        echo "version=$VERSION" >> $GITHUB_OUTPUT
+        echo "Releasing version: $VERSION"
+
+    - name: Generate release notes
       id: changelog
       run: |
-        echo "## What's Changed" > RELEASE_NOTES.md
-        git log $(git describe --tags --abbrev=0 HEAD^)..HEAD --pretty=format:"- %s (%h)" >> RELEASE_NOTES.md
+        if [ -f CHANGELOG.md ]; then
+          # Extract current version section from CHANGELOG.md
+          VERSION=${{ steps.version.outputs.version }}
+          awk "/## \[$VERSION\]/,/## \[/" CHANGELOG.md | head -n -1 > RELEASE_NOTES.md
+
+          # If extraction failed or is empty, use git log
+          if [ ! -s RELEASE_NOTES.md ]; then
+            echo "## What's Changed in v$VERSION" > RELEASE_NOTES.md
+            git log $(git describe --tags --abbrev=0 HEAD^)..HEAD --pretty=format:"- %s (%h)" >> RELEASE_NOTES.md
+          fi
+        else
+          echo "## What's Changed" > RELEASE_NOTES.md
+          git log $(git describe --tags --abbrev=0 HEAD^)..HEAD --pretty=format:"- %s (%h)" >> RELEASE_NOTES.md
+        fi
+
+        echo "" >> RELEASE_NOTES.md
+        echo "---" >> RELEASE_NOTES.md
+        echo "**Full Changelog**: https://github.com/${{ github.repository }}/compare/$(git describe --tags --abbrev=0 HEAD^)...v${{ steps.version.outputs.version }}" >> RELEASE_NOTES.md
 
     - name: Create GitHub Release
       uses: softprops/action-gh-release@v1
       with:
         body_path: RELEASE_NOTES.md
-        files: |
-          dist/*
+        files: dist/*
         draft: false
         prerelease: false
+        generate_release_notes: true
       env:
         GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
-    - name: Publish to PyPI (if token configured)
-      if: ${{ secrets.PYPI_API_TOKEN != '' }}
+    - name: Publish to PyPI
+      if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags/')
       env:
         TWINE_USERNAME: __token__
         TWINE_PASSWORD: ${{ secrets.PYPI_API_TOKEN }}
       run: |
-        twine upload dist/*
+        echo "📦 Publishing to PyPI..."
+        twine upload dist/* --verbose
+        echo "✅ Published to PyPI successfully!"