This is the first major commit after forking the original project. The
script has been almost completely rewritten to add new features.
- Implement AES-256 encryption with configurable PBKDF2 iterations (default 600k).
- Add Telegram integration for status updates and optional file uploads.
- Rework backup logic to use safe `sqlite3 .backup` method.
- Add GitHub Action to build/publish multi-arch Docker images and create
GitHub Releases on git tags.
BREAKING CHANGE: The project is not backward-compatible, configuration
and behavior are entirely different from the original version.
