added some docs

web/README.md

@@ -12,3 +12,86 @@ The webapp should serve under the / route the landing page which for both platfo
 - /app will have (airline) and (hotel) children which each have a layout.tsx and page.tsx where /app also has a parent layout defining layout.tsx and globals.css for any shared styling to avoid repretition.
 - /components/ is gonna have ui/ which defines things like Button, Card, DatePicker with generic definitions and any tracking or observation code. We then define feats/airline/ and feats/hotel/ as children of components with specific components like AirlineHero and HotelCard.
 - in /styles/ we define airline.css and hotel.css to tailor accents and styling for each.
+
+## How to Run
+
+```sh
+# install deps
+npm install
+
+# set store mode (hotel or airline)
+export STORE_MODE=hotel
+
+# run dev server
+npm run dev
+```
+
+Server runs on `http://localhost:3000`
+
+## Environment Variables
+
+| Variable | Description | Default | Example |
+|----------|-------------|---------|---------|
+| `HOSTNAME` | Server hostname | `localhost` | `localhost` |
+| `STORE_MODE` | Mode switch for platform | `hotel` | `hotel` or `airline` |
+| `NEXT_PUBLIC_API_BASE` | Public API base URL | `http://localhost:3000` | `http://localhost:3000` |
+| `NEXT_PUBLIC_APP_ENV` | Application environment | `dev` | `dev`, `prod` |
+| `NEXT_PUBLIC_HOVER_THRESHOLD` | Hover dwell threshold (ms) | `1200` | `1200` |
+| `BACKEND_URL` | Backend service URL | `http://localhost:5000` | `http://localhost:5000` |
+
+## Routes
+
+### Public Pages
+- `/` — Landing page (mode-aware root)
+- `/hotel` — Hotel mode landing
+- `/hotel/products` — Hotel catalog
+- `/airline` — Airline mode landing
+- `/airline/products` — Flight catalog
+- `/admin/experiments` — Experiment management UI
+
+### API Routes
+- `GET /api/session` — Fetch or create session, sets httpOnly cookie
+- `GET /api/pricing?productId=X&sessionId=Y&experimentId=Z` — Get product price from provider
+- `POST /api/ingest` — Ingest event to Kafka via backend
+- `GET /api/admin/experiments` — List all experiments
+- `POST /api/admin/experiments/start` — Start new experiment for session
+- `POST /api/admin/experiments/stop` — Stop experiment by ID
+
+## Event Catalog
+
+All events are ingested via `POST /api/ingest` and follow the `EventBase` schema. Below are the 17 canonical events:
+
+| Event Name | Category | Payload Example |
+|------------|----------|-----------------|
+| `session_start` | Session | `{ sessionId, experimentId?, storeMode, ts, page, eventName, userAgent? }` |
+| `page_view` | Navigation | `{ sessionId, experimentId?, storeMode, ts, page: "/hotel", eventName: "page_view" }` |
+| `view_item_page` | Discovery | `{ sessionId, storeMode, ts, page: "/hotel/products", productId: "H001", eventName: "view_item_page" }` |
+| `learn_more_about_item` | Discovery | `{ sessionId, storeMode, ts, page, productId, eventName: "learn_more_about_item" }` |
+| `add_item_to_cart` | Cart | `{ sessionId, storeMode, ts, page, productId, eventName: "add_item_to_cart" }` |
+| `remove_item` | Cart | `{ sessionId, storeMode, ts, page, productId, eventName: "remove_item" }` |
+| `checkout_start` | Cart | `{ sessionId, storeMode, ts, page, eventName: "checkout_start" }` |
+| `purchase_complete` | Cart | `{ sessionId, storeMode, ts, page, eventName: "purchase_complete", metadata?: { total: 500 } }` |
+| `search` | Filter/Search | `{ sessionId, storeMode, ts, page, eventName: "search", metadata: { query: "paris" } }` |
+| `filter_for_date` | Filter/Search | `{ sessionId, storeMode, ts, page, eventName: "filter_for_date", metadata: { from: "2025-01-15", to: "2025-01-20" } }` |
+| `filter_for_amenities` | Filter/Search | `{ sessionId, storeMode, ts, page, eventName: "filter_for_amenities", metadata: { amenities: ["wifi", "pool"] } }` |
+| `filter_for_price` | Filter/Search | `{ sessionId, storeMode, ts, page, eventName: "filter_for_price", metadata: { min: 100, max: 500 } }` |
+| `sort_change` | Filter/Search | `{ sessionId, storeMode, ts, page, eventName: "sort_change", metadata: { sort: "price_asc" } }` |
+| `hover_over_title` | Dwell signal | `{ sessionId, storeMode, ts, page, productId?, eventName: "hover_over_title", metadata: { duration: 1500 } }` |
+| `hover_over_paragraph` | Dwell signal | `{ sessionId, storeMode, ts, page, productId?, eventName: "hover_over_paragraph", metadata: { duration: 2000 } }` |
+| `hover_over_link` | Dwell signal | `{ sessionId, storeMode, ts, page, productId?, eventName: "hover_over_link", metadata: { href: "/hotel/products" } }` |
+| `hover_over_button` | Dwell signal | `{ sessionId, storeMode, ts, page, productId?, eventName: "hover_over_button", metadata: { label: "Book Now" } }` |
+
+## Architecture
+
+### Route Groups
+- `(hotel)` — Hotel mode pages
+- `(airline)` — Airline mode pages
+- `api/*` — API routes (session, pricing, ingest, admin)
+
+### Middleware Flow
+1. Request arrives at Next.js
+2. Session middleware checks for `phantom_session_id` cookie
+3. If missing, `/api/session` mints new session + sets cookie
+4. Store mode (`STORE_MODE` env) determines rendered page variant
+5. Client-side components fetch pricing via `/api/pricing`
+6. User interactions emit events to `/api/ingest` → Kafka