🛡️ Sentinel: [MEDIUM] Add missing Strict-Transport-Security and X-XSS-Protection headers

[davidruzicka]

🚨 Severity: MEDIUM
💡 Vulnerability: Missing Strict-Transport-Security header to enforce HTTPS and missing X-XSS-Protection: 0 to disable legacy browser auditors (which is the current industry best practice recommended by OWASP).
🎯 Impact: Without HSTS, clients may be vulnerable to downgrade attacks. Without X-XSS-Protection: 0, older browsers with flawed built-in auditors can sometimes be exploited.
🔧 Fix: Appended both headers to the middleware that sets security headers in src/transport/http-transport.ts.
✅ Verification: Ran unit tests src/transport/http-transport-security.test.ts to ensure headers are verified correctly, and ran the full suite via npm run test to verify no regressions.

---

PR created automatically by Jules for task 462714723753174629 started by @davidruzicka

[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.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ All tests successful. No failed tests found.

📢 Thoughts on this report? Let us know!