Added three Python Dockerfile variants with security best practices:
- Dockerfile.uv: Fast builds with UV package manager (recommended)
- Dockerfile.pip: Traditional pip-based workflow
- Dockerfile.distroless: Maximum security with no shell
Features across all templates:
- Multi-stage builds for minimal image size
- Non-root user execution
- BuildKit cache mounts for fast rebuilds
- Tini init for proper signal handling
- Health checks and OCI labels
- Comprehensive README with customization guide
