Add glue layer: MenuNode replaces MenuItem, remove /internal/menu-items API

- Context processor: get_navigation_tree() replaces get_all_menu_items()
- Menu admin service: MenuItem → MenuNode (container_type/container_id pattern)
- Remove /internal/menu-items endpoint (other apps query menu_nodes directly)
- Remove menu_items relationship from Post model
- Templates: item.post.X → item.X
- Add glue submodule

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

bp/menu_items/services/menu_items.py

@@ -2,7 +2,7 @@ from __future__ import annotations
 
 from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy import select, func
-from shared.models.menu_item import MenuItem
+from glue.models.menu_node import MenuNode
 from models.ghost_content import Post
 
 
@@ -10,30 +10,23 @@ class MenuItemError(ValueError):
     """Base error for menu item service operations."""
 
 
-async def get_all_menu_items(session: AsyncSession) -> list[MenuItem]:
+async def get_all_menu_items(session: AsyncSession) -> list[MenuNode]:
     """
-    Get all menu items (excluding deleted), ordered by sort_order.
-    Eagerly loads the post relationship.
+    Get all menu nodes (excluding deleted), ordered by sort_order.
     """
-    from sqlalchemy.orm import selectinload
-
     result = await session.execute(
-        select(MenuItem)
-        .where(MenuItem.deleted_at.is_(None))
-        .options(selectinload(MenuItem.post))
-        .order_by(MenuItem.sort_order.asc(), MenuItem.id.asc())
+        select(MenuNode)
+        .where(MenuNode.deleted_at.is_(None), MenuNode.depth == 0)
+        .order_by(MenuNode.sort_order.asc(), MenuNode.id.asc())
     )
     return list(result.scalars().all())
 
 
-async def get_menu_item_by_id(session: AsyncSession, item_id: int) -> MenuItem | None:
-    """Get a menu item by ID (excluding deleted)."""
-    from sqlalchemy.orm import selectinload
-
+async def get_menu_item_by_id(session: AsyncSession, item_id: int) -> MenuNode | None:
+    """Get a menu node by ID (excluding deleted)."""
     result = await session.execute(
-        select(MenuItem)
-        .where(MenuItem.id == item_id, MenuItem.deleted_at.is_(None))
-        .options(selectinload(MenuItem.post))
+        select(MenuNode)
+        .where(MenuNode.id == item_id, MenuNode.deleted_at.is_(None))
     )
     return result.scalar_one_or_none()
 
@@ -42,9 +35,9 @@ async def create_menu_item(
     session: AsyncSession,
     post_id: int,
     sort_order: int | None = None
-) -> MenuItem:
+) -> MenuNode:
     """
-    Create a new menu item.
+    Create a MenuNode + ContainerRelation for a page.
     If sort_order is not provided, adds to end of list.
     """
     # Verify post exists and is a page
@@ -60,32 +53,34 @@ async def create_menu_item(
     # If no sort_order provided, add to end
     if sort_order is None:
         max_order = await session.scalar(
-            select(func.max(MenuItem.sort_order))
-            .where(MenuItem.deleted_at.is_(None))
+            select(func.max(MenuNode.sort_order))
+            .where(MenuNode.deleted_at.is_(None), MenuNode.depth == 0)
         )
         sort_order = (max_order or 0) + 1
 
-    # Check for duplicate (same post, not deleted)
+    # Check for duplicate (same page, not deleted)
     existing = await session.scalar(
-        select(MenuItem).where(
-            MenuItem.post_id == post_id,
-            MenuItem.deleted_at.is_(None)
+        select(MenuNode).where(
+            MenuNode.container_type == "page",
+            MenuNode.container_id == post_id,
+            MenuNode.deleted_at.is_(None),
         )
     )
     if existing:
-        raise MenuItemError(f"Menu item for this page already exists.")
+        raise MenuItemError("Menu item for this page already exists.")
 
-    menu_item = MenuItem(
-        post_id=post_id,
-        sort_order=sort_order
+    menu_node = MenuNode(
+        container_type="page",
+        container_id=post_id,
+        label=post.title,
+        slug=post.slug,
+        feature_image=post.feature_image,
+        sort_order=sort_order,
     )
-    session.add(menu_item)
+    session.add(menu_node)
     await session.flush()
 
-    # Reload with post relationship
-    await session.refresh(menu_item, ["post"])
-
-    return menu_item
+    return menu_node
 
 
 async def update_menu_item(
@@ -93,10 +88,10 @@ async def update_menu_item(
     item_id: int,
     post_id: int | None = None,
     sort_order: int | None = None
-) -> MenuItem:
-    """Update an existing menu item."""
-    menu_item = await get_menu_item_by_id(session, item_id)
-    if not menu_item:
+) -> MenuNode:
+    """Update an existing menu node."""
+    menu_node = await get_menu_item_by_id(session, item_id)
+    if not menu_node:
         raise MenuItemError(f"Menu item {item_id} not found.")
 
     if post_id is not None:
@@ -110,35 +105,38 @@ async def update_menu_item(
         if not post.is_page:
             raise MenuItemError("Only pages can be added as menu items, not posts.")
 
-        # Check for duplicate (same post, different menu item)
+        # Check for duplicate (same page, different menu node)
         existing = await session.scalar(
-            select(MenuItem).where(
-                MenuItem.post_id == post_id,
-                MenuItem.id != item_id,
-                MenuItem.deleted_at.is_(None)
+            select(MenuNode).where(
+                MenuNode.container_type == "page",
+                MenuNode.container_id == post_id,
+                MenuNode.id != item_id,
+                MenuNode.deleted_at.is_(None),
             )
         )
         if existing:
-            raise MenuItemError(f"Menu item for this page already exists.")
+            raise MenuItemError("Menu item for this page already exists.")
 
-        menu_item.post_id = post_id
+        menu_node.container_id = post_id
+        menu_node.label = post.title
+        menu_node.slug = post.slug
+        menu_node.feature_image = post.feature_image
 
     if sort_order is not None:
-        menu_item.sort_order = sort_order
+        menu_node.sort_order = sort_order
 
     await session.flush()
-    await session.refresh(menu_item, ["post"])
 
-    return menu_item
+    return menu_node
 
 
 async def delete_menu_item(session: AsyncSession, item_id: int) -> bool:
-    """Soft delete a menu item."""
-    menu_item = await get_menu_item_by_id(session, item_id)
-    if not menu_item:
+    """Soft delete a menu node."""
+    menu_node = await get_menu_item_by_id(session, item_id)
+    if not menu_node:
         return False
 
-    menu_item.deleted_at = func.now()
+    menu_node.deleted_at = func.now()
     await session.flush()
 
     return True
@@ -147,17 +145,17 @@ async def delete_menu_item(session: AsyncSession, item_id: int) -> bool:
 async def reorder_menu_items(
     session: AsyncSession,
     item_ids: list[int]
-) -> list[MenuItem]:
+) -> list[MenuNode]:
     """
-    Reorder menu items by providing a list of IDs in desired order.
-    Updates sort_order for each item.
+    Reorder menu nodes by providing a list of IDs in desired order.
+    Updates sort_order for each node.
     """
     items = []
     for index, item_id in enumerate(item_ids):
-        menu_item = await get_menu_item_by_id(session, item_id)
-        if menu_item:
-            menu_item.sort_order = index
-            items.append(menu_item)
+        menu_node = await get_menu_item_by_id(session, item_id)
+        if menu_node:
+            menu_node.sort_order = index
+            items.append(menu_node)
 
     await session.flush()
 
@@ -174,7 +172,6 @@ async def search_pages(
     Search for pages (not posts) by title.
     Returns (pages, total_count).
     """
-    # Build search filter
     filters = [
         Post.is_page == True,  # noqa: E712
         Post.status == "published",