Rewrite README for post-decoupling architecture

Remove stale /adopt endpoint reference, document submodules, all
services, glue integration, checkout flow, and domain events.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

README.md

@@ -1,71 +1,84 @@
 # Cart App
 
-Shopping cart, checkout, and order management service for the Rose Ash cooperative marketplace.
-
-## Overview
-
-This is the **cart** microservice, split from the Rose Ash monolith. It handles:
-
-- **Shopping cart** - Add/remove products, view cart, cart summary API
-- **Checkout** - SumUp payment integration with hosted checkout
-- **Orders** - Order listing, detail view, payment status tracking
-- **Calendar bookings** - Calendar entry cart items and checkout integration
+Shopping cart, checkout, and order management service for the Rose Ash cooperative.
 
 ## Architecture
 
-- **Framework:** Quart (async Flask)
-- **Database:** PostgreSQL 16 via SQLAlchemy 2.0 (async)
-- **Payments:** SumUp Hosted Checkout
-- **Frontend:** HTMX + Jinja2 templates + Tailwind CSS
+One of four Quart microservices sharing a single PostgreSQL database:
 
-## Directory Structure
+| App | Port | Domain |
+|-----|------|--------|
+| blog (coop) | 8000 | Auth, blog, admin, menus, snippets |
+| market | 8001 | Product browsing, Suma scraping |
+| **cart** | 8002 | Shopping cart, checkout, orders |
+| events | 8003 | Calendars, bookings, tickets |
+
+## Structure
 
 ```
-app.py                  # Quart application factory
+app.py                  # Application factory (create_base_app + blueprints)
+path_setup.py           # Adds project root + app dir to sys.path
+config/app-config.yaml  # App URLs, SumUp config
+models/                 # Cart-domain models
+  order.py              #   Order, OrderItem
+  page_config.py        #   PageConfig (per-page SumUp credentials)
 bp/
-  cart/                 # Cart blueprint (add, view, checkout, webhooks)
-    routes.py
-    api.py              # Internal API (server-to-server, CSRF-exempt)
-    login_helper.py     # Cart merge on login
-    services/           # Business logic layer
-  order/                # Single order detail blueprint
-    routes.py
-    filters/qs.py       # Query string helpers
-  orders/               # Order listing blueprint
-    routes.py
-    filters/qs.py
-templates/
-  _types/cart/          # Cart templates
-  _types/order/         # Single order templates
-  _types/orders/        # Order listing templates
-entrypoint.sh           # Docker entrypoint (migrations + server start)
-Dockerfile              # Container build
-.gitea/workflows/ci.yml # CI/CD pipeline
+  cart/                 # Cart blueprint
+    global_routes.py    #   Add to cart, checkout, webhooks, return page
+    page_routes.py      #   Page-scoped cart and checkout
+    overview_routes.py  #   Cart overview / summary page
+    api.py              #   Internal API (/internal/cart/summary)
+    services/           #   Business logic
+      checkout.py       #     Order creation, SumUp integration
+      check_sumup_status.py  #  Payment status polling
+      calendar_cart.py  #     Calendar entry cart queries
+      page_cart.py      #     Page-scoped cart queries
+      get_cart.py       #     Cart item queries
+      identity.py       #     Cart identity (user_id / session_id)
+      total.py          #     Price calculations
+      clear_cart_for_order.py  # Soft-delete cart after checkout
+  order/                # Single order detail view
+  orders/               # Order listing view
+templates/              # Jinja2 templates
+entrypoint.sh           # Docker entrypoint
+Dockerfile
+shared/                 # Submodule → git.rose-ash.com/coop/shared.git
+glue/                   # Submodule → git.rose-ash.com/coop/glue.git
+```
+
+## Cross-App Integration
+
+- **Internal API:** `GET /internal/cart/summary` returns cart count + total for the current session/user. Called by blog and market context processors.
+- **Calendar entries:** Checkout marks CalendarEntries (events domain) as "ordered" via `glue/services/order_lifecycle.py` — not by direct model write.
+- **Payment confirmation:** When SumUp payment confirms, entries are marked "provisional" via the same glue service.
+- **Domain events:** Emits `order.created` and `order.paid` events for observability.
+- **Login adoption:** Anonymous cart/entries are adopted when `user.logged_in` event fires (handled by `glue/handlers/login_handlers.py`).
+
+## Checkout Flow
+
+```
+1. User clicks "Checkout"
+2. create_order_from_cart() creates Order + OrderItems
+3. glue: claim_entries_for_order() marks CalendarEntries as "ordered"
+4. emit: order.created event
+5. SumUp hosted checkout created, user redirected
+6. SumUp webhook / return page triggers check_sumup_status()
+7. If PAID: glue: confirm_entries_for_order(), emit: order.paid
 ```
 
 ## Running
 
 ```bash
-# Set environment variables
-export APP_MODULE=app:app
 export DATABASE_URL_ASYNC=postgresql+asyncpg://user:pass@localhost/coop
 export REDIS_URL=redis://localhost:6379/0
 export SECRET_KEY=your-secret-key
 
-# Run the server
 hypercorn app:app --reload --bind 0.0.0.0:8002
 ```
 
-## Cross-App Communication
-
-The cart app exposes internal API endpoints at `/internal/cart/` for other services:
-
-- `GET /internal/cart/summary` - Cart count and total for the current session/user
-- `POST /internal/cart/adopt` - Adopt anonymous cart items after user login
-
 ## Docker
 
 ```bash
-docker build -t cart:latest .
-docker run -p 8002:8000 --env-file .env cart:latest
+docker build -t cart .
+docker run -p 8002:8000 --env-file .env cart
 ```