🛡️ Sentinel: [MEDIUM] Add subprocess timeout to prevent worker thread exhaustion

[ManupaKDU]

🚨 Severity: MEDIUM
💡 Vulnerability: The subprocess.call execution for the ping command lacked a python-level timeout. If the underlying OS command hangs indefinitely, it could lead to thread pool exhaustion, causing a Denial of Service (DoS) within the scanner application.
🎯 Impact: The thread pool workers would wait indefinitely for the hung process, reducing the capacity to scan further IPs and potentially stalling the entire application.
🔧 Fix: Added a timeout argument to subprocess.call set to timeout_val + 2 as a defense-in-depth measure. Also added a try...except subprocess.TimeoutExpired block to catch and log the timeout securely without crashing the worker or leaking stack traces.
✅ Verification: Ran python3 -m unittest test_testping1.py and verified all tests pass, including the new test_is_reachable_subprocess_timeout.

---

PR created automatically by Jules for task 2790952053129446253 started by @ManupaKDU

[google-labs-jules]

👋 Jules, reporting for duty! I'm here to lend a hand with this pull request.

When you start a review, I'll add a 👀 emoji to each comment to let you know I've read it. I'll focus on feedback directed at me and will do my best to stay out of conversations between you and other bots or reviewers to keep the noise down.

I'll push a commit with your requested changes shortly after. Please note there might be a delay between these steps, but rest assured I'm on the job!

For more direct control, you can switch me to Reactive Mode. When this mode is on, I will only act on comments where you specifically mention me with @jules. You can find this option in the Pull Request section of your global Jules UI settings. You can always switch back!

New to Jules? Learn more at jules.google/docs.

---

For security, I will only act on instructions from the user who triggered this task.