Decouple cross-app models: move canonical definitions to shared/models/

- Move 6 model files to shared/models/ (ghost_content, order, page_config,
  market, market_place, calendars) so apps import from shared, not each other
- Fix auth templates: replace url_for('auth.*') with coop_url() for
  cross-app compatibility
- Fix TYPE_CHECKING import in sumup.py to use shared.models.order
- Delete dead infrastructure/cart_loader.py (inverted dependency)
- Update models/__init__.py to export all new models

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

browser/app/payments/sumup.py

@@ -9,7 +9,7 @@ from quart import current_app
 from shared.config import config
 
 if TYPE_CHECKING:
-    from cart.models.order import Order
+    from shared.models.order import Order
 
 SUMUP_BASE_URL = "https://api.sumup.com/v0.1"
 

browser/templates/_types/auth/_main_panel.html

@@ -18,7 +18,7 @@
           {% endif %}
         {% endif %}
       </div>
-      <form action="{{ url_for('auth.logout')|host }}" method="post">
+      <form action="{{ coop_url('/auth/logout/') }}" method="post">
         <input type="hidden" name="csrf_token" value="{{ csrf_token() }}">
         <button
           type="submit"

browser/templates/_types/auth/_newsletter_toggle.html

@@ -1,6 +1,6 @@
 <div id="nl-{{ un.newsletter_id }}" class="flex items-center">
   <button
-    hx-post="{{ url_for('auth.toggle_newsletter', newsletter_id=un.newsletter_id) }}"
+    hx-post="{{ coop_url('/auth/newsletter/' ~ un.newsletter_id ~ '/toggle/') }}"
     hx-headers='{"X-CSRFToken": "{{ csrf_token() }}"}'
     hx-target="#nl-{{ un.newsletter_id }}"
     hx-swap="outerHTML"

browser/templates/_types/auth/_newsletters_panel.html

@@ -22,7 +22,7 @@
                 {# No subscription row yet — show an off toggle that will create one #}
                 <div id="nl-{{ item.newsletter.id }}" class="flex items-center">
                   <button
-                    hx-post="{{ url_for('auth.toggle_newsletter', newsletter_id=item.newsletter.id) }}"
+                    hx-post="{{ coop_url('/auth/newsletter/' ~ item.newsletter.id ~ '/toggle/') }}"
                     hx-headers='{"X-CSRFToken": "{{ csrf_token() }}"}'
                     hx-target="#nl-{{ item.newsletter.id }}"
                     hx-swap="outerHTML"

browser/templates/_types/auth/check_email.html

@@ -22,7 +22,7 @@
 
       <p class="mt-6 text-sm">
         <a
-          href="{{ url_for('auth.login_form')|host }}"
+          href="{{ coop_url('/auth/login/') }}"
           class="text-stone-600 dark:text-stone-300 hover:underline"
         >
           ← Back

browser/templates/_types/auth/login.html

@@ -14,7 +14,7 @@
         {% endif %}
 
         <form
-          method="post" action="{{ url_for('auth.start_login')|host }}"
+          method="post" action="{{ coop_url('/auth/start/') }}"
           class="mt-6 space-y-5"
         >
           <input type="hidden" name="csrf_token" value="{{ csrf_token() }}">