[Build] feat: Add Vercel web app and additional backend modules

## GitHub Update **Repository:** [MKWcorp/CINTAI](https://github.com/MKWcorp/CINTAI) **Author:** MKWcorp **Date:** 11/9/2025, 7:15:31 AM **Commit:** [`064b01b`](https://github.com/MKWcorp/CINTAI/commit/064b01bc4b0e81e94e9056c53765a0c613355acc) ### Commit Message feat: Add Vercel web app and additional backend modules - Add cintai-web/ folder (Next.js app for Vercel deployment) * API route: /api/chat connecting to VPS backend * Frontend: Modern chat interface with Tailwind CSS * Config: next.config.js, tailwind.config.ts, tsconfig.json - Add modular handlers/ * consultation_handler.py * location_handler.py * email_handler.py * booking_handler.py * reminder_handler.py * image_handler.py - Add email & calendar integration * authenticate_gmail.py * calendar_helper.py * email_helper.py - Add documentation * DATABASE_STRUCTURE.md * TESTING.md - Add utilities * database_utils.py * handle_text_consultation_new.py * test_webhook.py - Update Dockerfile and requirements Ready for Vercel deployment with same backend endpoint --- _This story was imported from historical commits._