Build a hotel channel manager and booking engine

You are a developer who builds hospitality software.
I work in Hospitality & Travel: a hotel group with its own booking site. This work matters to guests and travellers.

## Goal
Build a direct booking engine with rates, availability and inventory synced to online travel agencies.

## What matters in Hospitality & Travel
- People involved: front office; revenue manager; housekeeping; food and beverage; guests; OTAs and travel agents; sales and events team.
- Rules and standards that usually apply: guest and fire safety; food-safety rules (FSSAI in India, local health codes); guest data privacy; OTA platform rules; tourism licences and taxes such as GST on room tariffs.
- Numbers that matter: occupancy rate; ADR; RevPAR; guest review score; direct-booking share; repeat-guest rate; cancellation rate.
- Common risks to plan for: empty rooms in the off season; bad reviews; overbooking; dependence on OTA commissions; safety incidents.
- Rules differ by country. If I have not said where I work, ask me, and do not present one country's law as if it applied everywhere.

## What I will give you
- Property and room types: [ROOMS]
- OTAs to connect: [e.g. Booking.com, Expedia through a channel API]
- Payment and taxes: [GATEWAY, TAX RULES]
- Stack: [STACK]
- Anything else you should know: [EXTRA CONTEXT, or "none"]

## How to work through it
1. Summarise what you understood about the product, its users and the launch scope. Point out anything unclear or contradictory and ask before you guess.
2. Build room types, rate plans, seasons and restrictions.
3. Build availability calendar with overbooking protection.
4. Build the booking engine with add-ons and promo codes.
5. Sync inventory and rates with a channel manager API.
6. Build reservations management, check-in and check-out.
7. Build guest emails before and after stay.
8. Build reports: occupancy, ADR, RevPAR.
9. Give a launch checklist covering security, performance, SEO, accessibility, backups and monitoring.
10. List what is deliberately out of scope for version 1 and what to build next.

## What to deliver
- Plan and data model
- Phase-by-phase build
- Availability and sync design
- Booking flow
- Reports

## Expert rules
- Build mobile first and make every screen work from 360px wide upwards, with labels, keyboard support and 4.5:1 contrast.
- Validate every input on the server, use prepared statements, hash passwords, protect forms with CSRF tokens and check roles on every admin action.
- Give complete files with full paths; never write "rest of the code stays the same".
- Respect seasonal demand, booking-platform rules and guest safety. If anything in my plan or inputs conflicts with them, say so plainly and suggest a fix.
- Do not invent facts, figures, laws, sources or quotes. Label anything you had to assume with "Assumption:" and tell me how to check it.

## Format
- Start with the plan (stack, structure, data model, screens), then build in numbered phases.
- Use tables for data models and endpoint lists.
- End each phase with how to run and test it.

## Before you answer
Check your draft against this list and fix anything that fails:
- The answer is practical enough to use today without rewriting.
- Every item under "What to deliver" is complete, specific to my inputs and usable as it is, with no placeholders left for me to guess.
- Where it applies, it shows the likely effect on occupancy rate and guest review score.

If something essential is missing, ask me up to 3 short questions first. Otherwise, start.