Add attach/detach glue calls to menu items, markets, and page config CRUD

Wire up ContainerRelation tracking via attach_child/detach_child in:
- menu_items: create, update (re-link on post change), delete
- markets: create (including revive), soft_delete
- page config: creation in update_features and update_sumup routes

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

bp/menu_items/services/menu_items.py

@@ -4,6 +4,7 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy import select, func
 from glue.models.menu_node import MenuNode
 from models.ghost_content import Post
+from glue.services.relationships import attach_child, detach_child
 
 
 class MenuItemError(ValueError):
@@ -79,6 +80,7 @@ async def create_menu_item(
     )
     session.add(menu_node)
     await session.flush()
+    await attach_child(session, "page", post_id, "menu_node", menu_node.id)
 
     return menu_node
 
@@ -117,6 +119,7 @@ async def update_menu_item(
         if existing:
             raise MenuItemError("Menu item for this page already exists.")
 
+        old_post_id = menu_node.container_id
         menu_node.container_id = post_id
         menu_node.label = post.title
         menu_node.slug = post.slug
@@ -127,6 +130,10 @@ async def update_menu_item(
 
     await session.flush()
 
+    if post_id is not None and post_id != old_post_id:
+        await detach_child(session, "page", old_post_id, "menu_node", menu_node.id)
+        await attach_child(session, "page", post_id, "menu_node", menu_node.id)
+
     return menu_node
 
 
@@ -138,6 +145,7 @@ async def delete_menu_item(session: AsyncSession, item_id: int) -> bool:
 
     menu_node.deleted_at = func.now()
     await session.flush()
+    await detach_child(session, "page", menu_node.container_id, "menu_node", menu_node.id)
 
     return True