Add attach/detach glue calls to calendar and market CRUD

Wire up ContainerRelation tracking via attach_child/detach_child in:
- calendars: create (including revive), soft_delete
- markets: create (including revive), soft_delete

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

bp/calendars/services/calendars.py

@@ -5,6 +5,7 @@ from sqlalchemy.ext.asyncio import AsyncSession
 
 from models.calendars import Calendar
 from blog.models.ghost_content import Post  # for FK existence checks
+from glue.services.relationships import attach_child, detach_child
 import unicodedata
 import re
 
@@ -66,6 +67,7 @@ async def soft_delete(sess: AsyncSession, post_slug: str, calendar_slug: str) ->
 
     cal.deleted_at = utcnow()
     await sess.flush()
+    await detach_child(sess, "page", cal.container_id, "calendar", cal.id)
     return True
 
 async def create_calendar(sess: AsyncSession, post_id: int, name: str) -> Calendar:
@@ -98,12 +100,14 @@ async def create_calendar(sess: AsyncSession, post_id: int, name: str) -> Calend
         if existing.deleted_at is not None:
             existing.deleted_at = None  # revive
             await sess.flush()
+            await attach_child(sess, "page", post_id, "calendar", existing.id)
             return existing
         raise CalendarError(f'Calendar with slug "{slug}" already exists for post {post_id}.')
 
     cal = Calendar(container_type="page", container_id=post_id, name=name, slug=slug)
     sess.add(cal)
     await sess.flush()
+    await attach_child(sess, "page", post_id, "calendar", cal.id)
     return cal