🛡️ Sentinel: [CRITICAL] Fix exposed database password in setup command

[keough99]

🚨 Severity: CRITICAL
💡 Vulnerability: The levelerdb setup command in leveler/commands.py accepted the MySQL database password as a plaintext argument. When a bot owner ran this command in a public server channel, the database password was exposed to all server members who could view the channel and was permanently logged in Discord's message history.
🎯 Impact: This allowed unauthorized users to view the backend database password, potentially leading to a complete compromise of the leveling database if the database host was publicly accessible or if the credentials were reused.
🔧 Fix: Added a security check (if ctx.guild:) to enforce that the levelerdb setup command can only be executed in Direct Messages (DMs). If it is accidentally run in a public server, the bot immediately warns the user, halts execution, and attempts to delete the command message to minimize exposure.
✅ Verification: Ensure the bot is running, attempt to use [p]levelerdb setup host user pass db 3306 in a server channel, and verify that it immediately deletes the message and returns a security warning. Verify that it still works in DMs.

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PR created automatically by Jules for task 7989220437383505210 started by @keough99

[google-labs-jules]

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