Add tests for SMS handler: - SendCode with valid phone number - SendCode with invalid phone (returns 400) - SendCode with missing phone (validation error) - SendCode when service not configured (returns 503) Coverage: handler 27.7% → 28.6%
Add tests for SMS handler: - SendCode with valid phone number - SendCode with invalid phone (returns 400) - SendCode with missing phone (validation error) - SendCode when service not configured (returns 503) Coverage: handler 27.7% → 28.6%