🔒 Fix hardcoded database credentials

[tsainez]

🎯 What: The vulnerability fixed
Hardcoded database credentials in php/oop/database.php

⚠️ Risk: The potential impact if left unfixed
Hardcoded secrets are a clear security risk. Malicious actors who gain access to the source code could use these credentials to access the database directly.

🛡️ Solution: How the fix addresses the vulnerability
Replaced the hardcoded credentials with environment variables, specifically DB_HOST, DB_NAME, DB_USER, and DB_PASS. This ensures that sensitive information is no longer stored in version control and can be securely configured per environment.

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PR created automatically by Jules for task 10863809030302161187 started by @tsainez

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