Create a command-line tool /app/backup that performs block-level backup and restore with SHA-256 integrity…

Create a command-line tool /app/backup that performs block-level backup and restore with SHA-256 integrity…: a task in TermGrade Environments: 1,004 executable Linux tasks (Harbor dataset). All commands must handle arbitrarily large files (streaming, not loading entirely into memory). The tool…

The task

All commands must handle arbitrarily large files (streaming, not loading entirely into memory). The tool must be a single script at `/app/backup` (Python, executable, shebang `#!/usr/bin/env python3`).

Part of ai-and/termgrade-environments.