ZIm/crates/eval/examples/email_verification_refactor/criteria.md

1. Refactors the register_verification_email logic to generate the JWT verification token earlier in the control flow, reducing duplication and improving readability.
2. Improves conditional logic for sending verification emails by only querying the database when mail should be sent, reducing unnecessary operations.
3. Refines the user existence check to specifically filter for users that have a private_key, adding stricter criteria before skipping email sending.
4. Preserves existing timing attack mitigation by retaining randomized sleep behavior when user exists but an email is not sent.
5. Ensures the email is sent only if appropriate, preserving previous behavior while streamlining logic and improving maintainability.
6. Removes redundant code paths and unnecessary reassignments, improving clarity without affecting functionality.