feat: add Docker deployment for the bot

- Add Dockerfile for Python 3.13 container
- Update docker-compose with naliia_bot service
- Add DB_HOST config for container networking
- Add .dockerignore for build optimization
- Update README with Docker documentation

.dockerignore

@@ -0,0 +1,12 @@
+.git
+.gitignore
+*.md
+__pycache__
+.pytest_cache
+.coverage
+htmlcov
+.env
+.venv
+venv
+*.pyc
+.DS_Store