Run shell commands in an E2B sandbox and stream stdout/stderr live

Documented steps

1. Create a sandbox with the E2B SDK, then use the commands module: Python `sandbox.commands.run('ls -l')`, JS `await sandbox.commands.run('ls -l')` (https://e2b.dev/docs/commands)
2. To stream output while a long command runs, pass callbacks: JS `sandbox.commands.run(cmd, { onStdout: (data) => ..., onStderr: (data) => ... })`; Python `sandbox.commands.run(cmd, on_stdout=lambda d: print(d), on_stderr=lambda d: print(d))` (https://e2b.dev/docs/commands/streaming)
3. The returned result object carries the exit code and captured output after completion; a non-zero exit raises/returns an error you should handle
4. Install extra packages at runtime with plain shell: `pip install X`, `npm install X`, `apt-get install X` (Debian-based images) — these persist only for that sandbox instance