🛡️ Sentinel: [CRITICAL] Fix SQL Injection in Metadata Generator

[thebearwithabite]

🚨 Severity: CRITICAL
💡 Vulnerability: SQL injection vulnerability in metadata_generator.py. The save_file_metadata method constructed a SQL INSERT OR REPLACE query by directly interpolating the keys from the metadata dictionary into the query string as column names. This bypassed parameterization and allowed potential execution of arbitrary SQL if an attacker could control the keys of the metadata dictionary.
🎯 Impact: Allowed execution of arbitrary SQL statements on the database, which could lead to data leakage, modification, or complete database destruction.
🔧 Fix: Implemented an explicit schema allowlist. The code now dynamically queries SQLite's PRAGMA table_info to get the actual column names of the file_metadata table, and then filters the untrusted metadata dictionary keys to ensure only valid columns are included in the SQL statement.
✅ Verification: Run python3 test_metadata.py to ensure normal functionality works correctly. A local test script verified that the vulnerable behavior has been stopped and no errors are raised for invalid columns.

---

PR created automatically by Jules for task 6663360943278694884 started by @thebearwithabite

[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.