feat: per-page carts with overview, page-scoped checkout, and split blueprints (Phase 4)

Splits the monolithic cart blueprint into three: cart_overview (GET /),
page_cart (/<page_slug>/), and cart_global (webhook, return, add).

- New page_cart.py service: get_cart_for_page(), get_calendar_entries_for_page(), get_cart_grouped_by_page()
- clear_cart_for_order() and create_order_from_cart() accept page_post_id for scoping
- Cart app hydrates page_slug via url_value_preprocessor/url_defaults/hydrate_page
- Context processor provides page-scoped cart data when g.page_post exists
- Internal API /internal/cart/summary accepts ?page_slug= for page-scoped counts
- Overview template shows page cards with item counts and totals
- Page cart template reuses show_cart() macro with page-specific header

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

templates/_types/cart/_cart.html

@@ -103,7 +103,7 @@
         {% if g.user %}
           <form
             method="post"
-            action="{{ url_for('cart.checkout')|host }}"
+            action="{{ url_for('page_cart.page_checkout')|host if page_post is defined and page_post else url_for('cart_global.checkout')|host }}"
             class="w-full"
           >
             <input type="hidden" name="csrf_token" value="{{ csrf_token() }}">

templates/_types/cart/checkout_error.html

@@ -27,7 +27,7 @@
 
     <div>
       <a
-        href="{{ url_for('cart.view_cart')|host }}"
+        href="{{ cart_url('/') }}"
         class="inline-flex items-center px-3 py-2 text-xs sm:text-sm rounded-full border border-stone-300 bg-white hover:bg-stone-50 transition"
       >
         <i class="fa fa-shopping-cart mr-2" aria-hidden="true"></i>

templates/_types/cart/header/_header.html

@@ -1,7 +1,7 @@
 {% import 'macros/links.html' as links %}
 {% macro header_row(oob=False) %}
   {% call links.menu_row(id='cart-row', oob=oob) %}
-    {% call links.link(url_for('cart.view_cart'), hx_select_search ) %}
+    {% call links.link(cart_url('/'), hx_select_search ) %}
       <i class="fa fa-shopping-cart"></i>
       <h2 class="text-xl font-bold">cart</h2>
     {% endcall %}

templates/_types/cart/overview/_main_panel.html

@@ -0,0 +1,128 @@
+<div class="max-w-full px-3 py-3 space-y-3">
+  {% if not page_groups or (page_groups | length == 0) %}
+    <div class="rounded-2xl border border-dashed border-stone-300 bg-white/80 p-6 sm:p-8 text-center">
+      <div class="inline-flex h-10 w-10 sm:h-12 sm:w-12 items-center justify-center rounded-full bg-stone-100 mb-3">
+        <i class="fa fa-shopping-cart text-stone-500 text-sm sm:text-base" aria-hidden="true"></i>
+      </div>
+      <p class="text-base sm:text-lg font-medium text-stone-800">
+        Your cart is empty
+      </p>
+    </div>
+
+  {% else %}
+    {# Check if there are any items at all across all groups #}
+    {% set ns = namespace(has_items=false) %}
+    {% for grp in page_groups %}
+      {% if grp.cart_items or grp.calendar_entries %}
+        {% set ns.has_items = true %}
+      {% endif %}
+    {% endfor %}
+
+    {% if not ns.has_items %}
+      <div class="rounded-2xl border border-dashed border-stone-300 bg-white/80 p-6 sm:p-8 text-center">
+        <div class="inline-flex h-10 w-10 sm:h-12 sm:w-12 items-center justify-center rounded-full bg-stone-100 mb-3">
+          <i class="fa fa-shopping-cart text-stone-500 text-sm sm:text-base" aria-hidden="true"></i>
+        </div>
+        <p class="text-base sm:text-lg font-medium text-stone-800">
+          Your cart is empty
+        </p>
+      </div>
+    {% else %}
+      <div class="space-y-4">
+        {% for grp in page_groups %}
+          {% if grp.cart_items or grp.calendar_entries %}
+
+            {% if grp.post %}
+              {# Page cart card #}
+              <a
+                href="{{ cart_url('/' + grp.post.slug + '/') }}"
+                class="block rounded-2xl border border-stone-200 bg-white shadow-sm hover:shadow-md hover:border-stone-300 transition p-4 sm:p-5"
+              >
+                <div class="flex items-start gap-4">
+                  {% if grp.post.feature_image %}
+                    <img
+                      src="{{ grp.post.feature_image }}"
+                      alt="{{ grp.post.title }}"
+                      class="h-16 w-16 rounded-xl object-cover border border-stone-200 flex-shrink-0"
+                    >
+                  {% else %}
+                    <div class="h-16 w-16 rounded-xl bg-stone-100 flex items-center justify-center flex-shrink-0">
+                      <i class="fa fa-store text-stone-400 text-xl" aria-hidden="true"></i>
+                    </div>
+                  {% endif %}
+
+                  <div class="flex-1 min-w-0">
+                    <h3 class="text-base sm:text-lg font-semibold text-stone-900 truncate">
+                      {{ grp.post.title }}
+                    </h3>
+
+                    <div class="mt-1 flex flex-wrap gap-2 text-xs text-stone-600">
+                      {% if grp.product_count > 0 %}
+                        <span class="inline-flex items-center gap-1 px-2 py-0.5 rounded-full bg-stone-100">
+                          <i class="fa fa-box-open" aria-hidden="true"></i>
+                          {{ grp.product_count }} item{{ 's' if grp.product_count != 1 }}
+                        </span>
+                      {% endif %}
+                      {% if grp.calendar_count > 0 %}
+                        <span class="inline-flex items-center gap-1 px-2 py-0.5 rounded-full bg-stone-100">
+                          <i class="fa fa-calendar" aria-hidden="true"></i>
+                          {{ grp.calendar_count }} booking{{ 's' if grp.calendar_count != 1 }}
+                        </span>
+                      {% endif %}
+                    </div>
+                  </div>
+
+                  <div class="text-right flex-shrink-0">
+                    <div class="text-lg font-bold text-stone-900">
+                      &pound;{{ "%.2f"|format(grp.total) }}
+                    </div>
+                    <div class="mt-1 text-xs text-emerald-700 font-medium">
+                      View cart &rarr;
+                    </div>
+                  </div>
+                </div>
+              </a>
+
+            {% else %}
+              {# Orphan bucket (items without a page) #}
+              <div class="rounded-2xl border border-dashed border-amber-300 bg-amber-50/60 p-4 sm:p-5">
+                <div class="flex items-start gap-4">
+                  <div class="h-16 w-16 rounded-xl bg-amber-100 flex items-center justify-center flex-shrink-0">
+                    <i class="fa fa-shopping-cart text-amber-500 text-xl" aria-hidden="true"></i>
+                  </div>
+
+                  <div class="flex-1 min-w-0">
+                    <h3 class="text-base sm:text-lg font-semibold text-stone-900">
+                      Other items
+                    </h3>
+                    <div class="mt-1 flex flex-wrap gap-2 text-xs text-stone-600">
+                      {% if grp.product_count > 0 %}
+                        <span class="inline-flex items-center gap-1 px-2 py-0.5 rounded-full bg-amber-100">
+                          <i class="fa fa-box-open" aria-hidden="true"></i>
+                          {{ grp.product_count }} item{{ 's' if grp.product_count != 1 }}
+                        </span>
+                      {% endif %}
+                      {% if grp.calendar_count > 0 %}
+                        <span class="inline-flex items-center gap-1 px-2 py-0.5 rounded-full bg-amber-100">
+                          <i class="fa fa-calendar" aria-hidden="true"></i>
+                          {{ grp.calendar_count }} booking{{ 's' if grp.calendar_count != 1 }}
+                        </span>
+                      {% endif %}
+                    </div>
+                  </div>
+
+                  <div class="text-right flex-shrink-0">
+                    <div class="text-lg font-bold text-stone-900">
+                      &pound;{{ "%.2f"|format(grp.total) }}
+                    </div>
+                  </div>
+                </div>
+              </div>
+            {% endif %}
+
+          {% endif %}
+        {% endfor %}
+      </div>
+    {% endif %}
+  {% endif %}
+</div>

templates/_types/cart/overview/_oob_elements.html

@@ -0,0 +1,24 @@
+{% extends 'oob_elements.html' %}
+
+{# OOB elements for cart overview HTMX navigation #}
+
+{% from '_types/root/_oob_menu.html' import mobile_menu with context %}
+
+{% block oobs %}
+
+  {% from '_types/root/_n/macros.html' import oob_header with context %}
+  {{oob_header('root-header-child', 'cart-header-child', '_types/cart/header/_header.html')}}
+
+  {% from '_types/root/header/_header.html' import header_row with context %}
+  {{ header_row(oob=True) }}
+{% endblock %}
+
+
+{% block mobile_menu %}
+  {% include '_types/cart/_nav.html' %}
+{% endblock %}
+
+
+{% block content %}
+      {% include "_types/cart/overview/_main_panel.html" %}
+{% endblock %}

templates/_types/cart/overview/index.html

@@ -0,0 +1,22 @@
+{% extends '_types/root/_index.html' %}
+
+{% block root_header_child %}
+  {% from '_types/root/_n/macros.html' import index_row with context %}
+  {% call index_row('cart-header-child', '_types/cart/header/_header.html') %}
+    {% block cart_header_child %}
+    {% endblock %}
+  {% endcall %}
+{% endblock %}
+
+
+{% block _main_mobile_menu %}
+{% include '_types/cart/_nav.html' %}
+{% endblock %}
+
+
+{% block aside %}
+{% endblock %}
+
+{% block content %}
+  {% include '_types/cart/overview/_main_panel.html' %}
+{% endblock %}

templates/_types/cart/page/_main_panel.html

@@ -0,0 +1,4 @@
+<div class="max-w-full px-3 py-3 space-y-3">
+    {% from '_types/cart/_cart.html' import show_cart with context %}
+    {{ show_cart() }}
+  </div>

templates/_types/cart/page/_oob_elements.html

@@ -0,0 +1,27 @@
+{% extends 'oob_elements.html' %}
+
+{# OOB elements for page cart HTMX navigation #}
+
+{% from '_types/root/_oob_menu.html' import mobile_menu with context %}
+
+{% block oobs %}
+
+  {% from '_types/root/_n/macros.html' import oob_header with context %}
+  {{oob_header('root-header-child', 'cart-header-child', '_types/cart/header/_header.html')}}
+
+  {% from '_types/cart/page/header/_header.html' import page_header_row with context %}
+  {{ page_header_row(oob=True) }}
+
+  {% from '_types/root/header/_header.html' import header_row with context %}
+  {{ header_row(oob=True) }}
+{% endblock %}
+
+
+{% block mobile_menu %}
+  {% include '_types/cart/_nav.html' %}
+{% endblock %}
+
+
+{% block content %}
+      {% include "_types/cart/page/_main_panel.html" %}
+{% endblock %}

templates/_types/cart/page/header/_header.html

@@ -0,0 +1,25 @@
+{% import 'macros/links.html' as links %}
+{% macro page_header_row(oob=False) %}
+  {% call links.menu_row(id='page-cart-row', oob=oob) %}
+    {% call links.link(cart_url('/' + page_post.slug + '/'), hx_select_search) %}
+      {% if page_post.feature_image %}
+      <img
+          src="{{ page_post.feature_image }}"
+          class="h-8 w-8 rounded-full object-cover border border-stone-300 flex-shrink-0"
+        >
+      {% endif %}
+      <span>
+        {{ page_post.title | truncate(160, True, '...') }}
+      </span>
+    {% endcall %}
+    {% call links.desktop_nav() %}
+      <a
+        href="{{ cart_url('/') }}"
+        class="inline-flex items-center gap-1.5 px-3 py-1.5 text-sm rounded-full border border-stone-300 bg-white hover:bg-stone-50 transition"
+      >
+        <i class="fa fa-arrow-left text-xs" aria-hidden="true"></i>
+        All carts
+      </a>
+    {% endcall %}
+  {% endcall %}
+{% endmacro %}

templates/_types/cart/page/index.html

@@ -0,0 +1,24 @@
+{% extends '_types/root/_index.html' %}
+
+{% block root_header_child %}
+  {% from '_types/root/_n/macros.html' import index_row with context %}
+  {% call index_row('cart-header-child', '_types/cart/header/_header.html') %}
+    {% block cart_header_child %}
+      {% from '_types/cart/page/header/_header.html' import page_header_row with context %}
+      {{ page_header_row() }}
+    {% endblock %}
+  {% endcall %}
+{% endblock %}
+
+
+{% block _main_mobile_menu %}
+{% include '_types/cart/_nav.html' %}
+{% endblock %}
+
+
+{% block aside %}
+{% endblock %}
+
+{% block content %}
+  {% include '_types/cart/page/_main_panel.html' %}
+{% endblock %}