Add shopper accounts, reviews, tracking, and seed_demo (#10)

## Summary
- Closes #9. Port shop-gated buyer accounts (register/login/profile, password reset, order history), purchase-gated reviews, and Stripe customer ids. Cards stay on Stripe.
- Slim public contact form to email + interest + message. Shipping tracking status, scan events, paste-in numbers, and EasyPost webhook when FEATURE_SHIPPING is on.
- Add template-neutral `seed_demo` (generic SKUs, demo shoppers, guest orders, tracking stubs). Prod refused. `--reset` deletes tagged demo rows after invoices.

## Test plan
- [ ] `cd site && uv run python manage.py test` (173 tests passed locally)
- [ ] Shop on: `/account/register`, login, profile, password reset, claim guest orders by email
- [ ] Shop off: `/account/` URLs absent; Sign in / Account links hidden
- [ ] Checkout as logged-in buyer stores `Order.user` and Stripe customer id; product review only after paid purchase
- [ ] Shipping on: portal paste-in tracking + EasyPost webhook updates status; shipping off: orders still work without tracking UI
- [ ] `seed_demo` refused in prod; `--reset` rebuilds tagged catalog/shoppers without deleting staff invoices

Reviewed-on: #10

site/shop/services.py

@@ -8,10 +8,10 @@ from decimal import Decimal
 
 from django.conf import settings
 from django.db import transaction
-from django.db.models import F, Sum
+from django.db.models import F, Q, Sum
 from django.utils import timezone
 
-from shop.models import Order, OrderItem, Product
+from shop.models import Order, OrderItem, Product, ProductReview
 
 logger = logging.getLogger(__name__)
 
@@ -156,6 +156,7 @@ def create_order_from_cart(
     customer_name: str = "",
     shipping_address: dict | None = None,
     notes: str = "",
+    user=None,
 ) -> Order:
     lines = cart_lines(session)
     if not lines:
@@ -169,6 +170,7 @@ def create_order_from_cart(
     with transaction.atomic():
         order = Order.objects.create(
             number=next_order_number(),
+            user=user if getattr(user, "is_authenticated", False) else None,
             email=email,
             customer_name=(customer_name or "").strip(),
             status=Order.Status.DRAFT,
@@ -191,6 +193,42 @@ def create_order_from_cart(
     return order
 
 
+def ensure_stripe_customer(user) -> str:
+    """Create or reuse a Stripe Customer. Card data never leaves Stripe."""
+    if not user or not getattr(user, "is_authenticated", False):
+        return ""
+    from accounts.services import get_customer_profile
+
+    profile = get_customer_profile(user)
+    if profile.stripe_customer_id:
+        return profile.stripe_customer_id
+    stripe = _stripe()
+    customer = stripe.Customer.create(
+        email=(user.email or user.username or "") or None,
+        name=(user.get_full_name() or "") or None,
+        metadata={"user_id": str(user.pk)},
+    )
+    customer_id = getattr(customer, "id", None) or customer.get("id") or ""
+    if not customer_id:
+        raise ShopError("Stripe did not return a customer id.")
+    profile.stripe_customer_id = customer_id
+    profile.save(update_fields=["stripe_customer_id", "updated_at"])
+    return customer_id
+
+
+def remember_stripe_customer(order: Order, customer_id: str) -> None:
+    customer_id = (customer_id or "").strip()
+    if not customer_id or not order.user_id:
+        return
+    from accounts.services import get_customer_profile
+
+    profile = get_customer_profile(order.user)
+    if profile.stripe_customer_id:
+        return
+    profile.stripe_customer_id = customer_id
+    profile.save(update_fields=["stripe_customer_id", "updated_at"])
+
+
 def create_checkout_session(order: Order, *, success_url: str, cancel_url: str) -> str:
     stripe = _stripe()
     line_items = [
@@ -208,14 +246,27 @@ def create_checkout_session(order: Order, *, success_url: str, cancel_url: str)
     ]
     if not line_items:
         raise ShopError("Order has no items.")
-    session = stripe.checkout.Session.create(
-        mode="payment",
-        customer_email=order.email or None,
-        line_items=line_items,
-        metadata={"shop_order_id": str(order.pk), "order_number": order.number},
-        success_url=success_url,
-        cancel_url=cancel_url,
-    )
+    params = {
+        "mode": "payment",
+        "line_items": line_items,
+        "metadata": {"shop_order_id": str(order.pk), "order_number": order.number},
+        "success_url": success_url,
+        "cancel_url": cancel_url,
+    }
+    customer_id = ""
+    if order.user_id:
+        try:
+            customer_id = ensure_stripe_customer(order.user)
+        except ShopError:
+            raise
+        except Exception:
+            logger.exception("stripe customer create failed for order %s", order.number)
+    if customer_id:
+        params["customer"] = customer_id
+        params["payment_intent_data"] = {"setup_future_usage": "on_session"}
+    else:
+        params["customer_email"] = order.email or None
+    session = stripe.checkout.Session.create(**params)
     order.stripe_checkout_session_id = session.id
     order.hosted_checkout_url = session.url or ""
     order.status = Order.Status.OPEN
@@ -249,7 +300,9 @@ def _notify_pos(order: Order) -> None:
     enqueue_online_sale(order)
 
 
-def mark_paid(order: Order, *, stripe_id: str = "") -> None:
+def mark_paid(
+    order: Order, *, stripe_id: str = "", stripe_customer_id: str = ""
+) -> None:
     if order.status == Order.Status.PAID:
         return
     with transaction.atomic():
@@ -261,6 +314,7 @@ def mark_paid(order: Order, *, stripe_id: str = "") -> None:
         locked.paid_at = timezone.now()
         locked.save(update_fields=["status", "paid_at", "updated_at"])
     order.refresh_from_db()
+    remember_stripe_customer(order, stripe_customer_id)
     try:
         send_order_email(order)
     except Exception:
@@ -303,3 +357,28 @@ def send_order_email(order: Order) -> bool:
     mail.attach_alternative(html, "text/html")
     mail.send(fail_silently=False)
     return True
+
+
+_REVIEWABLE_STATUSES = (Order.Status.PAID, Order.Status.FULFILLED)
+
+
+def qualifying_order_for_review(user, product: Product) -> Order | None:
+    if not user or not getattr(user, "is_authenticated", False):
+        return None
+    email = (user.email or user.username or "").strip()
+    qs = (
+        Order.objects.filter(
+            items__product=product,
+            status__in=_REVIEWABLE_STATUSES,
+        )
+        .filter(Q(user=user) | Q(email__iexact=email))
+        .distinct()
+        .order_by("-paid_at", "-created_at")
+    )
+    return qs.first()
+
+
+def user_has_reviewed(user, product: Product) -> bool:
+    if not user or not getattr(user, "is_authenticated", False):
+        return False
+    return ProductReview.objects.filter(user=user, product=product).exists()