- Add manifest.json generation script (scripts/generate-manifest.php)
- Add Updater::cleanStaleFiles() that removes files not in manifest
- Add /api/v1/update/clean endpoint with backward compatibility
- Add configurable update_protected_paths in config/invoiceshelf.php
- Update frontend to use clean step instead of delete step
- Add GitHub Actions release workflow triggered on version tags
- Add .github/release.yml for auto-generated changelog categories
- Update Makefile to include manifest generation and scripts directory
