🛡️ Sentinel: [CRITICAL] Fix command injection via execSync

[google-labs-jules]

🚨 Severity: CRITICAL
💡 Vulnerability: Multiple instances of execSync interpolated with string formats or shell commands containing potential dynamic variables, allowing for command injection through shell metacharacters.
🎯 Impact: Arbitrary shell command execution if user inputs like projectDir or arguments are manipulated.
🔧 Fix: Replaced execSync with execFileSync, passing arguments safely as an array (or directly replacing pipe sequences). Suppressed outputs using stdio config over shell redirection (2>/dev/null). For counting log entries, changed to native string.split('\\n').filter(Boolean).length in JS.
✅ Verification: Ran node --test tests/*.test.mjs confirming the test suite still passes without regression.

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PR created automatically by Jules for task 16741957117261790542 started by @raccioly

[google-labs-jules]

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