fix: Prevent SQL injection in reservation setting

[max-ostapenko]

🎯 What: The vulnerability fixed is a potential SQL Injection through the reservation property when prepending the SET @@reservation statement to queries or preOps.
⚠️ Risk: A malicious user or configuration could inject arbitrary SQL statements using ' and ; characters which would be executed with the privileges of the script running the queries.
🛡️ Solution: Implemented strict regex validation /^[a-zA-Z0-9\-_/]+$/ on reservation properties via preprocessConfig to verify that they are safe (only containing alphanumeric characters, hyphens, underscores, and forward slashes) before utilizing them in templates. Throws an error for invalid formats instead of rendering.

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PR created automatically by Jules for task 11716247562806139373 started by @max-ostapenko

[google-labs-jules]

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