🛡️ Sentinel: [CRITICAL] Fix command argument injection

[google-labs-jules]

🚨 Severity: CRITICAL
💡 Vulnerability: Command argument injection when passing user-controlled paths to std::process::Command (e.g., for git clone). If a repository path starts with a hyphen (e.g., -u or --upload-pack=...), git might interpret it as a flag.
🎯 Impact: Arbitrary command execution or unexpected behavior.
🔧 Fix: Added -- before the source and destination paths in git clone commands to signal the end of options.
✅ Verification: Ran cargo check and cargo test to verify the fix does not introduce regressions.

Also recorded learning in .jules/sentinel.md.

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PR created automatically by Jules for task 4317620969320902637 started by @euxaristia

[google-labs-jules]

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[github-actions]

Thanks for the contribution. A couple of things will help us review this faster:

• Link the issue this addresses (Closes #123). For protocol changes, open an issue first.
• This changes Rust source but no tests changed. Tests are required for fixes and strongly encouraged for features.

See CONTRIBUTING.md. Update the PR and these notes will clear automatically.