explain-block

name	explain-block
description	Explain whether a shell command would be blocked by Codex Safeguard and why.

Explain a command using Codex Safeguard.

Steps:

1. Run bunx codex-safeguard explain <command>.
2. If the command is blocked, report the matched rule and the reason.
3. If the command is allowed, say that no blocking rule matched.
4. Suggest a safer alternative when the command is destructive.