Fix potential TypeError and unhandled exceptions in /create_invite_link route

[akil9979]

Problem

The /create_invite_link API assumes that the inviter always exists and has an invites array.

If checkInviteLink() returns an empty result, the code tries to access:

response[0].invites

which causes:

TypeError: Cannot read properties of undefined (reading 'invites')

Invalid inviter_id or server_id values can also cause MongoDB errors.

Expected Behavior

• Invalid IDs should return a proper error.
• Missing inviter data should be handled safely.
• The API should not crash when no invite data exists.

Suggested Fix

• Validate inviter_id and server_id.
• Check if response is empty before accessing response[0].invites.
• Wrap database operations in try/catch to handle errors gracefully.

[akil9979]

Hi Maintainers, I would like to work on this issue under GSSoC'26. Kindly assign it to me if approved. Thank you!