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/blog/ghost_db.py

@@ -286,17 +286,28 @@ class DBClient:
 
         rows: List[Post] = list((await self.sess.execute(q)).scalars())
 
-        # Load PageConfigs from cart service (page_configs lives in db_cart)
+        # Load PageConfigs directly (page_configs now lives in db_blog)
         post_ids = [p.id for p in rows]
         pc_map: Dict[int, dict] = {}
         if post_ids:
-            from shared.infrastructure.data_client import fetch_data
+            from shared.models.page_config import PageConfig
             try:
-                raw_pcs = await fetch_data("cart", "page-configs-batch",
-                    params={"container_type": "page", "ids": ",".join(str(i) for i in post_ids)})
-                if isinstance(raw_pcs, list):
-                    for pc in raw_pcs:
-                        pc_map[pc["container_id"]] = pc
+                pc_result = await self.sess.execute(
+                    select(PageConfig).where(
+                        PageConfig.container_type == "page",
+                        PageConfig.container_id.in_(post_ids),
+                    )
+                )
+                for pc in pc_result.scalars().all():
+                    pc_map[pc.container_id] = {
+                        "id": pc.id,
+                        "container_type": pc.container_type,
+                        "container_id": pc.container_id,
+                        "features": pc.features or {},
+                        "sumup_merchant_code": pc.sumup_merchant_code,
+                        "sumup_api_key": pc.sumup_api_key,
+                        "sumup_checkout_prefix": pc.sumup_checkout_prefix,
+                    }
             except Exception:
                 pass  # graceful degradation — pages render without features