Changes:
- Replaced simulated API call with real fetch() to /api/contact
- Added errorMessage state for custom error messages
- Implemented proper response handling for different status codes:
* 200: Success message and form reset
* 429: Rate limit error with time until retry
* 400/500: Display API error messages
- Enhanced rate limit error display with human-readable time formatting
- Added VERIFICATION_STEPS.md for manual testing guidance
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
