fix: restore trailing newline in CHANGELOG.md

The file requires a trailing newline for Spotless check to pass.

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: konard

CHANGELOG.md

@@ -47,3 +47,4 @@ This implementation:
   - `create-manual-changeset.mjs` - Manual fragment creation
 - Example code demonstrating library usage
 - Comprehensive documentation (README, CONTRIBUTING)
+