Fix cart template: use direct CartItem queries in market context

Market owns CartItem/Product — query directly with selectinload
so templates can access item.product.slug and other ORM attributes.
The cart service DTOs are for cross-domain consumers (blog, events).

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

app.py

@@ -17,26 +17,43 @@ async def market_context() -> dict:
     """
     Market app context processor.
 
-    - menu_items: direct DB query via glue layer
-    - cart_count/cart_total: via cart service (shared DB)
+    - menu_items: direct DB query
+    - cart/cart_count/cart_total: direct DB (market owns CartItem/Product)
     """
     from shared.infrastructure.context import base_context
     from shared.services.navigation import get_navigation_tree
     from shared.infrastructure.cart_identity import current_cart_identity
-    from shared.services.registry import services
+    from shared.models.market import CartItem
+    from sqlalchemy.orm import selectinload
 
     ctx = await base_context()
 
     ctx["menu_items"] = await get_navigation_tree(g.s)
 
-    # Cart data via service (replaces direct CartItem query)
+    # Market owns CartItem/Product — query directly for template compat
     ident = current_cart_identity()
-    summary = await services.cart.cart_summary(
-        g.s, user_id=ident["user_id"], session_id=ident["session_id"],
+    filters = [CartItem.deleted_at.is_(None)]
+    if ident["user_id"]:
+        filters.append(CartItem.user_id == ident["user_id"])
+    elif ident["session_id"]:
+        filters.append(CartItem.session_id == ident["session_id"])
+    else:
+        ctx["cart"] = []
+        ctx["cart_count"] = 0
+        ctx["cart_total"] = 0
+        return ctx
+
+    result = await g.s.execute(
+        select(CartItem).where(*filters).options(selectinload(CartItem.product))
     )
-    ctx["cart"] = summary.items
-    ctx["cart_count"] = summary.count
-    ctx["cart_total"] = float(summary.total)
+    cart_items = list(result.scalars().all())
+
+    ctx["cart"] = cart_items
+    ctx["cart_count"] = sum(ci.quantity for ci in cart_items)
+    ctx["cart_total"] = float(sum(
+        (ci.product.special_price or ci.product.regular_price or 0) * ci.quantity
+        for ci in cart_items if ci.product
+    ))
 
     return ctx