🛡️ Sentinel: [CRITICAL] Restrict shell_execute to allowed commands

[JustinWoodring]

This PR addresses a critical security vulnerability in slatron-server's Rhai scripting engine. Previously, the shell_execute function allowed execution of arbitrary shell commands. This change introduces:

1. Allowlist Enforcement: shell_execute is now restricted to a predefined list of safe commands: yt-dlp, ffmpeg, and ffprobe.
2. Argument Sanitization: For yt-dlp, the --exec argument is explicitly blocked to prevent command injection/bypass.
3. Security Tests: New tests in src/rhai_engine/security_test.rs verify that unauthorized commands (like ls) and dangerous arguments are correctly rejected with a "Security Alert".

This change prevents RCE via malicious or compromised scripts.

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PR created automatically by Jules for task 15446079692671839145 started by @JustinWoodring

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[claude]

Code Review

Good security improvement overall! This PR successfully restricts shell_execute from allowing arbitrary commands to a small allowlist. However, I found one security concern that should be addressed:

Security Issue: Incomplete argument restrictions for ffmpeg

Location:

slatron/slatron-server/src/rhai_engine/mod.rs

Lines 177 to 194 in 7cb68a1

	// Security Check: Block dangerous args for specific commands
	if cmd == "yt-dlp" {
	for arg in &args {
	let s = arg.to_string();
	if s.starts_with("--exec") {
	let err_msg = format!(
	"Security Alert: Argument '{}' is blocked for command '{}'.",
	s, cmd
	);
	tracing::error!("{}", err_msg);
	let mut map = rhai::Map::new();
	map.insert("code".into(), (-1 as i64).into());
	map.insert("stdout".into(), "".into());
	map.insert("stderr".into(), err_msg.into());
	return map;
	}
	}
	}

While the PR correctly blocks --exec for yt-dlp, ffmpeg and ffprobe are allowed without argument restrictions. This creates a security bypass opportunity.

Malicious content_loader scripts could exploit ffmpeg to overwrite arbitrary files and achieve code execution. For example, downloading malicious content from a remote URL and writing it to shell config files.

Context:
This doesn't block the PR since it's still a net security improvement over the previous state where ANY command could be executed. However, ffmpeg has many dangerous capabilities including arbitrary file I/O and network access that should be restricted.

Recommendation:
Add argument restrictions for ffmpeg/ffprobe similar to yt-dlp, such as blocking the -y flag, restricting output paths to safe directories, and validating remote URL inputs.

Otherwise, excellent work on the security hardening and comprehensive test coverage!