Split cart into 4 microservices: relations, likes, orders, page-config→blog

Phase 1 - Relations service (internal): owns ContainerRelation, exposes
get-children data + attach/detach-child actions. Retargeted events, blog,
market callers from cart to relations.

Phase 2 - Likes service (internal): unified Like model replaces ProductLike
and PostLike with generic target_type/target_slug/target_id. Exposes
is-liked, liked-slugs, liked-ids data + toggle action.

Phase 3 - PageConfig → blog: moved ownership to blog with direct DB queries,
removed proxy endpoints from cart.

Phase 4 - Orders service (public): owns Order/OrderItem + SumUp checkout
flow. Cart checkout now delegates to orders via create-order action.
Webhook/return routes and reconciliation moved to orders.

Phase 5 - Infrastructure: docker-compose, deploy.sh, Dockerfiles updated
for all 3 new services. Added orders_url helper and factory model imports.

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

blog/bp/post/services/post_data.py

@@ -1,6 +1,5 @@
 from ...blog.ghost_db import DBClient  # adjust import path
-from sqlalchemy import select
-from models.ghost_content import PostLike
+from shared.infrastructure.data_client import fetch_data
 from quart import g
 
 async def post_data(slug, session, include_drafts=False):
@@ -15,14 +14,10 @@ async def post_data(slug, session, include_drafts=False):
   # Check if current user has liked this post
   is_liked = False
   if g.user:
-      liked_record = await session.scalar(
-          select(PostLike).where(
-              PostLike.user_id == g.user.id,
-              PostLike.post_id == post["id"],
-              PostLike.deleted_at.is_(None),
-          )
-      )
-      is_liked = liked_record is not None
+      liked_data = await fetch_data("likes", "is-liked", params={
+          "user_id": g.user.id, "target_type": "post", "target_id": post["id"],
+      }, required=False)
+      is_liked = (liked_data or {}).get("liked", False)
 
   # Add is_liked to post dict
   post["is_liked"] = is_liked