- Create TypeScript interfaces (Role, RoleWithVoice, RolesResponse, GenerateRequest)
- Implement detectRoles() function for role detection
- Implement generateAudiobook() function for audio generation
- Implement checkHealth() function for backend health checks
- Add comprehensive error handling for network failures
- Use VITE_API_BASE_URL environment variable for configuration
- Add ApiError class for structured error handling
Requirements: 9.6, 9.7
