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/accounts/customer_urls.py

@@ -0,0 +1,62 @@
+from django.apps import apps
+from django.contrib.auth import views as auth_views
+from django.urls import path, reverse_lazy
+
+from accounts import views
+from accounts.forms import CustomerPasswordResetForm, CustomerSetPasswordForm
+
+app_name = "account"
+
+urlpatterns = [
+    path("", views.customer_home, name="home"),
+    path("login/", views.CustomerLoginView.as_view(), name="login"),
+    path("logout/", views.customer_logout, name="logout"),
+    path("register/", views.customer_register, name="register"),
+    path("profile/", views.customer_profile, name="profile"),
+    path(
+        "password-reset/",
+        auth_views.PasswordResetView.as_view(
+            template_name="accounts/password_reset_form.html",
+            email_template_name="accounts/password_reset_email.txt",
+            subject_template_name="accounts/password_reset_subject.txt",
+            form_class=CustomerPasswordResetForm,
+            success_url=reverse_lazy("account:password_reset_done"),
+        ),
+        name="password_reset",
+    ),
+    path(
+        "password-reset/done/",
+        auth_views.PasswordResetDoneView.as_view(
+            template_name="accounts/password_reset_done.html",
+        ),
+        name="password_reset_done",
+    ),
+    path(
+        "password-reset/<uidb64>/<token>/",
+        auth_views.PasswordResetConfirmView.as_view(
+            template_name="accounts/password_reset_confirm.html",
+            form_class=CustomerSetPasswordForm,
+            success_url=reverse_lazy("account:password_reset_complete"),
+        ),
+        name="password_reset_confirm",
+    ),
+    path(
+        "password-reset/complete/",
+        auth_views.PasswordResetCompleteView.as_view(
+            template_name="accounts/password_reset_complete.html",
+        ),
+        name="password_reset_complete",
+    ),
+]
+
+if apps.is_installed("shop"):
+    from shop import views as shop_views
+
+    urlpatterns += [
+        path("orders/", shop_views.account_order_list, name="orders"),
+        path(
+            "orders/<uuid:pk>/",
+            shop_views.account_order_detail,
+            name="order_detail",
+        ),
+    ]