📧 feat: email verification

[berry-13]

Summary

added email verification for secure sign-ups 💪

(forgot to change the branch name oops)

Change Type

• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

Testing

Email tested with gmail SMTP

Checklist

• My code adheres to this project's style guidelines
• I have performed a self-review of my own code
• I have commented in any complex areas of my code
• I have made pertinent documentation changes
• My changes do not introduce new warnings
• I have written tests demonstrating that my changes are effective or that my feature works
• Local unit tests pass with my changes
• Any changes dependent on mine have been merged and published in downstream modules.
• New documents have been locally validated with mkdocs

[Kevin-free]

@berry-13 Thank you for your contribution! I merged this PR. After registration, the backend often shows error: [sendEmail] connect ETIMEDOUT 108.xxx.xxx.108:465 (occasionally it can be sent successfully, it may be a network problem here)

But even if I receive the verification email, when I click the link "http://localhost:3080/verify?token=xxx&userId=xxx", it shows "Unexpected Application Error!
404 Not Found". What should I do?

[danny-avila]

some technical debt with this PR: unverified users can potentially remain unverified forever. the solution would be to utilize createNewUser with a TTL expiry option. Going to address this before merging