- Add verification code login endpoint to support passwordless authentication via email or phone
- Add send login verification code endpoint to initiate verification code delivery
- Implement verificationCodeLogin method in LoginService to handle verification code authentication
- Implement sendLoginVerificationCode method in LoginService to send verification codes to users
- Add VerificationCodeLoginRequest and related DTOs to support new login flow
- Add VerificationCodeLoginDto and SendLoginVerificationCodeDto for API request validation
- Implement verificationCodeLogin and sendLoginVerificationCode in LoginCoreService
- Add comprehensive Swagger documentation for new endpoints with proper status codes and responses
- Support test mode for verification code delivery with 206 Partial Content status
- Fix UsersService dependency injection in test specifications to use string token
- Enhance authentication options by providing passwordless login alternative to traditional password-based authentication
- Replace boolean assertions with structured result object checks in email service tests
- Update email service tests to verify success flag and isTestMode property
- Add error message assertions for failed email sending scenarios
- Change logger spy from 'log' to 'warn' for test mode email output
- Update test message to clarify emails are not actually sent in test mode
- Add code and createdAt properties to verification code stats mock data
- Fix TTL mock value from -1 to -2 to correctly represent non-existent keys
- Replace Inject decorator with direct UsersService type injection in LoginCoreService
- Ensure verification service tests properly mock TTL values during code verification
- Improve test coverage by validating complete response structures instead of simple booleans
