Add delete endpoint with confirm modal, keep items at quantity 0

- POST /delete/<product_id>/ removes the cart item entirely
- POST /quantity/ now clamps at 0 instead of deleting
- cart_delete_url Jinja global registered for template

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

app.py

@@ -100,6 +100,7 @@ def create_app() -> "Quart":
     ])
 
     app.jinja_env.globals["cart_quantity_url"] = lambda product_id: f"/quantity/{product_id}/"
+    app.jinja_env.globals["cart_delete_url"] = lambda product_id: f"/delete/{product_id}/"
 
     # --- Page slug hydration (follows events/market app pattern) ---
 

bp/cart/global_routes.py

@@ -72,10 +72,30 @@ def register(url_prefix: str) -> Blueprint:
         existing = await g.s.scalar(select(CartItem).where(*filters))
 
         if existing:
-            if count <= 0:
-                await g.s.delete(existing)
-            else:
-                existing.quantity = count
+            existing.quantity = max(count, 0)
+            await g.s.flush()
+
+        resp = await make_response("", 200)
+        resp.headers["HX-Refresh"] = "true"
+        return resp
+
+    @bp.post("/delete/<int:product_id>/")
+    async def delete_item(product_id: int):
+        ident = current_cart_identity()
+
+        filters = [
+            CartItem.deleted_at.is_(None),
+            CartItem.product_id == product_id,
+        ]
+        if ident["user_id"] is not None:
+            filters.append(CartItem.user_id == ident["user_id"])
+        else:
+            filters.append(CartItem.session_id == ident["session_id"])
+
+        existing = await g.s.scalar(select(CartItem).where(*filters))
+
+        if existing:
+            await g.s.delete(existing)
             await g.s.flush()
 
         resp = await make_response("", 200)