feat: integrate changelog directly into PR merge commit

🔧 **Improved Changelog Integration:**

- Changelog is now appended to the PR merge commit message instead of creating a separate commit
- Version bump changes are included in the same amended merge commit
- Uses git commit --amend to modify the merge commit with both changelog and version changes
- Updated force push with --force-with-lease for safer history rewriting
- Cleaner git history with single commit containing all release information

**Benefits:**
- ✅ Single commit per release (cleaner history)
- ✅ Changelog directly visible in merge commit
- ✅ No additional 'chore: bump version' commits
- ✅ All release info consolidated in one place
- ✅ Safer force push with --force-with-lease

VERSION_WORKFLOW.md

@@ -84,6 +84,7 @@ Make sure these secrets are configured in your GitHub repository:
 
 - ✅ Automatic version bumping based on branch
 - ✅ AI-generated changelog using Claude Code CLI
+- ✅ Appends changelog to PR merge commit message
 - ✅ Runs tests before publishing
 - ✅ Builds the package before publishing
 - ✅ Creates git tags with changelog in tag message
@@ -102,7 +103,7 @@ The workflow automatically generates a standardized changelog for each release u
 - ⚡ **Performance** - Performance optimizations
 
 The generated changelog is included in:
-- The version bump commit message
+- The PR merge commit message (automatically appended)
 - The git tag message
 - The GitHub release notes