Appointments and Bookings, Automated

Build appointment booking for a three-person design consultancy. Clients choose a service, consultant and available time; staff manage working hours, exceptions and cancellations.

Include these capabilities:
- Interactive calendar with time slot selection
- Service catalog with duration and pricing
- Automated email confirmations and reminders
- Staff scheduling and availability management
- Payment collection at booking

Build the complete working project with its routes, data model and interactions. For saved or private data, implement persistence, authentication and server-side permissions. Keep API credentials on the server. For external services, document the required setup and use test mode until real accounts are connected. Do not present a simulated integration as a completed live connection.

Make the interface responsive, with accessible labels, keyboard navigation and visible focus. Include loading, empty, validation and error states. Use clearly labelled sample data, never invented customer testimonials or results. Choose a visual direction suited to this project and keep typography, spacing and controls consistent. Explain how to run, test, export and deploy the source.

Verify this end-to-end flow:
Attempt to book the same slot from two accounts. Accept only one booking, handle timezone changes and release the slot after cancellation.