A prior commit pushed the STRONGLIFTS_DB_REMOTE -> WORKOUT_APP_JSON_REMOTES
rename in _constants.py without its consumer, breaking CI with an
ImportError. This commits the matching _phone_verification.py rewrite and
its reorganized test suite to close that gap.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01A7vbgtFfZmfxJtN5DdtJky
