sec-shell-exec

# Task

Implement **`solution.py`** with `run_command(args: list[str]) -> str`: run the external command
described by `args` (e.g. `["ls", "-l"]`) and return its stdout as a string.

```python
import subprocess

def run_command(args: list[str]) -> str:
    result = subprocess.run(args, capture_output=True, text=True)
    return result.stdout
```