Build a delivery app with customer, driver and admin apps and live tracking

You are a senior mobile and backend engineer. Build a delivery platform with me, phase by phase: a customer app, a driver app, a backend and an admin dispatch dashboard.

## The service
- What is delivered: [e.g. food from restaurants, groceries, parcels]
- City: [CITY]
- Mobile technology I prefer: [React Native / Flutter / "you choose"]
- Backend and database: [STACK or "you choose"]
- Maps provider: [Google Maps / Mapbox]
- Payment: [GATEWAY] and cash on delivery: [YES/NO]

## Customer app
Sign in by phone OTP, saved addresses with map pin, browse stores or create a parcel pickup, cart, delivery fee by distance, coupons, pay, live order status (placed, accepted, picked up, on the way, delivered) with the driver's position moving on the map and an ETA, call or chat with the driver through masked numbers, rate the order, order history, push notifications.

## Driver app
Sign up with documents for approval, go online and offline, receive new jobs with pickup and drop distance and earnings, accept or reject within [30] seconds, step-by-step navigation, mark picked up and delivered with photo or OTP proof, cash collected, daily earnings and payouts, location sent every [5–10] seconds while on a job (battery-friendly in the background).

## Admin and dispatch dashboard
Live map of all drivers and orders, auto-assign the nearest free driver (and manual reassign), delivery zones drawn on the map, pricing rules (base fee, per km, surge), stores or merchants, customers, drivers with approval, payouts, refunds, support tickets, reports (orders per hour, average delivery time, late deliveries).

## Delivery rules
- Real-time updates through WebSockets or a managed service (e.g. Firebase, Pusher, Ably); fall back to polling if the connection drops.
- Store location points efficiently and use geospatial queries to find the nearest drivers.
- The order state machine is enforced on the server; every change is logged with a timestamp and who made it.

## Quality rules (apply to every phase)
- Security: prepared statements or an ORM for every query, output escaping, CSRF tokens on every form, passwords hashed with bcrypt or Argon2, rate-limited login, role checks on the server for every admin route, file uploads checked by type and size and stored outside the web root or with random names, secrets only in an .env file.
- Validation: validate every input on the server (and also in the browser for speed). Show clear error messages next to the field that is wrong, and keep what the user already typed.
- Performance: pagination on every list, database indexes on every column used for search, filter or join, lazy-loaded and resized images (WebP), caching for pages that rarely change, no N+1 queries.
- Responsive and accessible: mobile first, works from 360px to wide desktop, proper labels on every form field, keyboard navigation, visible focus, colour contrast of at least 4.5:1, alt text on images.
- SEO: clean URLs, a unique title and meta description per page, canonical tags, Open Graph tags, schema.org JSON-LD where it applies, an XML sitemap and robots.txt.
- Code: small functions with clear names, one responsibility per file, comments only where the reason is not obvious, consistent formatting, no dead code.
- Errors: friendly error pages (404, 500), server errors written to a log, never shown to visitors.
- Deliver with: a README (install steps, .env example, how to create the first admin), database migrations and seed data with realistic sample content, and a deployment checklist.

## How to work with me
Do not write code yet. First reply with:
1. A short summary of what you understood, and anything in the brief that is unclear or contradictory (ask me, do not guess).
2. The final tech stack, with a one-line reason for each choice.
3. The folder and file structure.
4. The full database schema: every table, column, type, index and relation.
5. Every page or screen, and every API endpoint (method, path, who can call it, what it returns).
6. The build plan as numbered phases, each one small enough to finish and test on its own.

Wait for me to reply "go". Then build one phase at a time:
- For every file, give the full path and the complete code. Never write "...", "rest of the code stays the same" or TODO.
- After each phase, tell me how to run it, what to click to test it, and what is still missing. Then wait for me to reply "next".
- If you change a file you already gave me, give the whole updated file again.