🛡️ Sentinel: [CRITICAL] Fix Path Traversal in Skill Importer

[thirdeyenation]

🚨 Severity: CRITICAL
💡 Vulnerability: Zip Slip (path traversal) vulnerability in helpers.skills_import._unzip_to_temp_dir. The function previously called z.extractall(target) without verifying whether the files inside the archive resolved to paths within the intended target directory. A maliciously crafted zip file containing relative paths (like ../escaped.txt) could write files outside the temporary directory, potentially overwriting sensitive system files or application code.
🎯 Impact: An attacker could upload or point the skill importer to a malicious .zip file that overwrites any writable file on the system, potentially achieving remote code execution (RCE) or altering project configurations.
🔧 Fix: Explicitly iterate over z.namelist() and compute the absolute, resolved path of each member before extraction using os.path.realpath. Then, verify that each path resides within the target directory using files.is_in_dir. If any path escapes, a ValueError is raised.
✅ Verification: Tested isolated functionality by creating a dummy zip with ../escaped.txt and ensuring the modified function intercepts the extraction and raises the expected error.

---

PR created automatically by Jules for task 9931150929452089158 started by @thirdeyenation

[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.